# 13086 - Golden Ratio Overheat
>author: Utin
###### tags: `recursion`
---
## Brief
See the code below
Similar to 12602 OuQ String
## Solution 0
```c=
#include <stdio.h>
#include <string.h>
int T, n;
char f0[2001], f1[2001];
long long int k, len[61];
char search(int n, long long int k);
int main() {
scanf("%d", &T);
while (T--) {
scanf("%s %s %d %lld", f0, f1, &n, &k);
len[0] = strlen(f0);
len[1] = strlen(f1);
for (int i = 2; i <= n; i++) {
len[i] = len[i-1] + len[i-2];
}
char ans = search(n, k);
printf("%c\n", ans);
}
}
char search(int n, long long int k) {
if (n == 0) return f0[k];
if (n == 1) return f1[k];
if (k < len[n-2]) return search(n-2, k);
return search(n-1, k-len[n-2]);
}
// By Utin
```
## Reference