diff --git a/2023207/main.cpp b/2023207/main.cpp
index 6113af6..c01c473 100644
--- a/2023207/main.cpp
+++ b/2023207/main.cpp
@@ -109,7 +109,7 @@ int main() {
         // do this column by column
         for (int j = 0; j < n; j++) {
             // diag of U is always 1, z[j] * U[j][j] = z[j], so k doesn't have to equal to j
-            for (int k = j + 1; k < n; k++) {
+            for (int k = j + 1; k < j + 3 && k < n; k++) {
                 Z[k] += Z[j] * get_content(k, j);
             }
         }
@@ -130,7 +130,7 @@ int main() {
         // printf("Starting U-1\n");
         for (int j = n - 1; j >= 0; j--) {
             // diag of U is always 1, z[j] * U[j][j] = z[j], so k doesn't have to equal to j
-            for (int k = 0; k < j; k++) {
+            for (int k = j - 1; k > j - 3 && k >= 0; k--) {
                 Z[k] += Z[j] * get_content(k, j);
             }
             // outputZ();