diff --git a/07/solution.c b/07/solution.c
index e7dff0d..cadd59a 100644
--- a/07/solution.c
+++ b/07/solution.c
@@ -51,7 +51,7 @@ entry *addent(entry *parent, int isdir, const char *name) {
     return e;
 }
 
-int main(void) {
+int main(int argc, char **argv) {
     char l[64];
     entry *root = calloc(1, sizeof(entry));
     root->isdir++;
@@ -84,7 +84,10 @@ int main(void) {
     }
 
     current = root;
-    required = 30000000UL - (70000000UL - root->size);
+    if (argc == 3)
+        required = strtoul(argv[2], NULL, 10) - (strtoul(argv[1], NULL, 10) - root->size);
+    else
+        required = 30000000UL - (70000000UL - root->size);
     do {
         if (current->n_entries) {
             current->n_entries--;