#include <stdio.h>
int rec(int n) {
if (n == 0) return 3;
else if (n == 1) return 0;
else if (n == 2) return 2;
return rec(n - 2) + rec(n - 3);
}
int main(void) {
for (int i = 0; i <= 50; i++) {
}
return 0;
}
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