diff --git a/thu2025kaoyan_b.cpp b/thu2025kaoyan_b.cpp
new file mode 100644
index 0000000..4a8aebb
--- /dev/null
+++ b/thu2025kaoyan_b.cpp
@@ -0,0 +1,322 @@
+#include <stdio.h>
+#include <string.h>
+
+#define MAXN 550
+#define QSIZE (3 * 500 * 500)
+
+enum posture {
+    pos_s,
+    pos_h, 
+    pos_v
+};
+
+struct q_node {
+    int row;
+    int col;
+    posture pos;
+};
+
+int T;
+int n, m;
+int dist_s[MAXN][MAXN], dist_h[MAXN][MAXN], dist_v[MAXN][MAXN];
+
+q_node q[QSIZE];
+int q_head = 0;
+int q_tail = 0;
+
+void q_clear() {
+    q_head = 0;
+    q_tail = 0;
+}
+
+bool q_empty() {
+    return q_head == q_tail;
+}
+
+void enq(q_node node) {
+    q[q_tail] = node;
+    q_tail++;
+    q_tail %= QSIZE;
+}
+
+q_node deq() {
+    q_node ret = q[q_head];
+    q_head++;
+    q_head %= QSIZE;
+    return ret;
+}
+
+int start_row, start_col;
+posture start_pos;
+int end_row, end_col;
+
+int map[MAXN][MAXN] = {0};
+// 0 = wall
+// 1 = ground
+
+bool valid_pos(int row, int col, posture pos) {
+    if (row >= n || col >= m || row < 0 || col < 0) {
+        return false;
+    }
+    if (pos == pos_s) {
+        return map[row][col] > 0;
+    } else if (pos == pos_h) {
+        return map[row][col] > 0 && map[row][col + 1] > 0;
+    } else if (pos == pos_v) {
+        return map[row][col] > 0 && map[row + 1][col] > 0;
+    } else {
+        // should not be here
+        return false;
+    }
+}
+
+int bfs() {
+    // init
+    q_clear();
+    for (int i = 0; i < n; ++i) {
+        for (int j = 0; j < m; ++j) {
+            dist_s[i][j] = -1;
+            dist_h[i][j] = -1;
+            dist_v[i][j] = -1;
+        }
+    }
+
+    if (start_pos == pos_s) {
+        dist_s[start_row][start_col] = 0;
+    } else if (start_pos == pos_h) {
+        dist_h[start_row][start_col] = 0;
+    } else if (start_pos == pos_v) {
+        dist_v[start_row][start_col] = 0;
+    }
+
+    q_node start_node = q_node {
+        .row = start_row,
+        .col = start_col,
+        .pos = start_pos,
+    };
+
+    enq(start_node);
+
+    while (!q_empty()) {
+        q_node cur_node = deq();
+
+        if (cur_node.row == end_row && cur_node.col == end_col && cur_node.pos == pos_s) {
+            return dist_s[end_row][end_col];
+        }
+
+        // printf("%d,%d, pos %d\n", cur_node.row, cur_node.col, cur_node.pos);
+
+        if (cur_node.pos == pos_s) {
+            int cur_dist = dist_s[cur_node.row][cur_node.col];
+            // left
+            if (valid_pos(cur_node.row, cur_node.col - 2, pos_h)) {
+                if (dist_h[cur_node.row][cur_node.col - 2] == -1) {
+                    dist_h[cur_node.row][cur_node.col - 2] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row,
+                        .col = cur_node.col - 2,
+                        .pos = pos_h,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // right
+            if (valid_pos(cur_node.row, cur_node.col + 1, pos_h)) {
+                if (dist_h[cur_node.row][cur_node.col + 1] == -1) {
+                    dist_h[cur_node.row][cur_node.col + 1] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row,
+                        .col = cur_node.col + 1,
+                        .pos = pos_h,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // up
+            if (valid_pos(cur_node.row - 2, cur_node.col, pos_v)) {
+                if (dist_v[cur_node.row - 2][cur_node.col] == -1) {
+                    dist_v[cur_node.row - 2][cur_node.col] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row - 2,
+                        .col = cur_node.col,
+                        .pos = pos_v,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // down
+            if (valid_pos(cur_node.row + 1, cur_node.col, pos_v)) {
+                if (dist_v[cur_node.row + 1][cur_node.col] == -1) {
+                    dist_v[cur_node.row + 1][cur_node.col] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row + 1,
+                        .col = cur_node.col,
+                        .pos = pos_v,
+                    };
+                    enq(new_node);
+                }
+            }
+        } else if (cur_node.pos == pos_h) {
+            int cur_dist = dist_h[cur_node.row][cur_node.col];
+            // left
+            if (valid_pos(cur_node.row, cur_node.col - 1, pos_s)) {
+                if (dist_s[cur_node.row][cur_node.col - 1] == -1) {
+                    dist_s[cur_node.row][cur_node.col - 1] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row,
+                        .col = cur_node.col - 1,
+                        .pos = pos_s,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // right
+            if (valid_pos(cur_node.row, cur_node.col + 2, pos_s)) {
+                if (dist_s[cur_node.row][cur_node.col + 2] == -1) {
+                    dist_s[cur_node.row][cur_node.col + 2] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row,
+                        .col = cur_node.col + 2,
+                        .pos = pos_s,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // up
+            if (valid_pos(cur_node.row - 1, cur_node.col, pos_h)) {
+                if (dist_h[cur_node.row - 1][cur_node.col] == -1) {
+                    dist_h[cur_node.row - 1][cur_node.col] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row - 1,
+                        .col = cur_node.col,
+                        .pos = pos_h,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // down
+            if (valid_pos(cur_node.row + 1, cur_node.col, pos_h)) {
+                if (dist_h[cur_node.row + 1][cur_node.col] == -1) {
+                    dist_h[cur_node.row + 1][cur_node.col] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row + 1,
+                        .col = cur_node.col,
+                        .pos = pos_h,
+                    };
+                    enq(new_node);
+                }
+            }
+        } else if (cur_node.pos == pos_v) {
+            int cur_dist = dist_v[cur_node.row][cur_node.col];
+            // left
+            if (valid_pos(cur_node.row, cur_node.col - 1, pos_v)) {
+                if (dist_v[cur_node.row][cur_node.col - 1] == -1) {
+                    dist_v[cur_node.row][cur_node.col - 1] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row,
+                        .col = cur_node.col - 1,
+                        .pos = pos_v,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // right
+            if (valid_pos(cur_node.row, cur_node.col + 1, pos_v)) {
+                if (dist_v[cur_node.row][cur_node.col + 1] == -1) {
+                    dist_v[cur_node.row][cur_node.col + 1] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row,
+                        .col = cur_node.col + 1,
+                        .pos = pos_v,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // up
+            if (valid_pos(cur_node.row - 1, cur_node.col, pos_s)) {
+                if (dist_s[cur_node.row - 1][cur_node.col] == -1) {
+                    dist_s[cur_node.row - 1][cur_node.col] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row - 1,
+                        .col = cur_node.col,
+                        .pos = pos_s,
+                    };
+                    enq(new_node);
+                }
+            }
+
+            // down
+            if (valid_pos(cur_node.row + 2, cur_node.col, pos_s)) {
+                if (dist_s[cur_node.row + 2][cur_node.col] == -1) {
+                    dist_s[cur_node.row + 2][cur_node.col] = cur_dist + 1;
+                    q_node new_node = q_node {
+                        .row = cur_node.row + 2,
+                        .col = cur_node.col,
+                        .pos = pos_s,
+                    };
+                    enq(new_node);
+                }
+            }
+        } else {
+            // Should not be here
+        }
+    }
+    return -1;
+}
+
+int main() {
+    scanf("%d", &T);
+    for (int _ = 0; _ < T; ++_) {
+        // Initialize
+        memset(map, 0, sizeof(map));
+        bool found_start = false;
+        scanf("%d %d", &n, &m);
+
+        // Read in map
+        char linebuf[MAXN] = {0};
+        for (int i = 0; i < n; ++i) {
+            scanf("%s", linebuf);
+            for (int j = 0; j < m; ++j) {
+                if (linebuf[j] == '#') {
+                    map[i][j] = 0;
+                } else if (linebuf[j] == '.' || linebuf[j] == 'E') {
+                    map[i][j] = 1;
+                } else if (linebuf[j] == 'X') {
+                    map[i][j] = 1;
+                    if (found_start == false) {
+                        start_row = i;
+                        start_col = j;
+                        start_pos = pos_s;
+                        // Assume this pos, if there are more X then change
+                        found_start = true;
+                    } else {
+                        if (j == start_col + 1 && i == start_row) {
+                            start_pos = pos_h;
+                        } else if (j == start_col && i == start_row + 1) {
+                            start_pos = pos_v;
+                        } else {
+                            // Should not be here
+                        }
+                    }
+                } else if (linebuf[j] == 'O') {
+                    map[i][j] = 1;
+                    end_row = i;
+                    end_col = j;
+                }
+            }
+        }
+
+        int ans = bfs();
+        printf("%d\n", ans);
+    }
+    
+    return 0;
+}
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