func_code_string: #include <bits/stdc++.h>   using namespace std;   int pro(int *a, int *b, int t, int s) {     int k = 0;     for (int i = 1; i < t; i++) {       if (b[i] != s) {         return 2;       }       if (b[i] == 0) {         k++;       }     }     if (k == (t - 1)) {       return 3;     }     return 1;   }   int main() {     int t, a[105], b[105];     a[0] = 0;     cin >> t;     for (int i = 1; i <= t; i++) {       cin >> a[i];       b[i - 1] = a[i] - a[i - 1];     }     if (t == 1) {       cout << a[1];     }     int c = pro(a, b, t, b[1]);     if (c == 3) {       cout << a[1];     } else if (c == 1) {       cout << a[t] + b[1];     } else {       cout << a[t];     }     return 0;   }   