Index: aoc2024.c
==================================================================
--- aoc2024.c
+++ aoc2024.c
@@ -13,14 +13,16 @@
     char *dontleft = data;
     char *dontrite = strstr(dontleft + 1, "don't()");
     for (;;) {
         char *mul = strstr(rest, "mul(");
         if (mul) {
+            // make sure `doleft` and `dorite` are to the left and right of `mul`
             while (dorite && (mul > dorite)) {
                 doleft = dorite;
                 dorite = strstr(dorite + 1, "do()");
             }
+            // also for `dontleft` and `dontrite`
             while (dontrite && (mul > dontrite)) {
                 dontleft = dontrite;
                 dontrite = strstr(dontrite + 1, "don't()");
             }
             rest = mul + 4;
@@ -31,10 +33,11 @@
                     if (isdigit((unsigned char)err[1])) {
                         rest = err + 1;
                         term[1] = (int)strtol(rest, &err, 10);
                         if (*err == ')') {
                             sumproducts += term[0] * term[1];
+                            // multiply by 0 if closest conditional to the left is "don't()"
                             sumproducts2 += (doleft >= dontleft) * (term[0] * term[1]);
                             rest = err + 1;
                         }
                     }
                 }