Index: aoc2024.c
==================================================================
--- aoc2024.c
+++ aoc2024.c
@@ -53,12 +53,30 @@
 
     int c[4];
     int maxbananas = 0, totalbananas = 0;
     for (c[0] = -9; c[0] < 10; c[0]++) {
         for (c[1] = -9; c[1] < 10; c[1]++) {
+            int c0c1 = c[0] + c[1];
+            if (c0c1 < -9) continue;
+            if (c0c1 > 9) continue;
             for (c[2] = -9; c[2] < 10; c[2]++) {
+                int c1c2 = c[1] + c[2];
+                int c0c1c2 = c[0] + c1c2;
+                if (c1c2 < -9) continue;
+                if (c1c2 > 9) continue;
+                if (c0c1c2 < -9) continue;
+                if (c0c1c2 > 9) continue;
                 for (c[3] = -9; c[3] < 10; c[3]++) {
+                    int c2c3 = c[2] + c[3];
+                    int c1c2c3 = c1c2 + c[3];
+                    int c0c1c2c3 = c0c1 + c2c3;
+                    if (c2c3 < -9) continue;
+                    if (c2c3 > 9) continue;
+                    if (c1c2c3 < -9) continue;
+                    if (c1c2c3 > 9) continue;
+                    if (c0c1c2c3 < -9) continue;
+                    if (c0c1c2c3 > 9) continue;
                     totalbananas = 0;
                     for (size_t s = 0; s < nsecrets; s++) {
                         int bananas = 0;
                         unsigned long long sec[2] = {0, secrets[s]};
                         int delta[4];