func_code_string: #include <bits/stdc++.h>   using namespace std;   long long f[50];   int main() {     int n;     cin >> f[0] >> f[1] >> n;     for (int i = 2; i <= n; i++) f[i] = f[i - 1] + f[i - 2];     cout << f[n];     return 0;   }   