#include <bits/stdc++.h>   using namespace std;   const int maxn = 410;   const int inf = 0x7fffffff;   int a[maxn];   int n;   int main() {     int ans = inf;     cin >> n;     for (int i = 1; i <= n; i++) cin >> a[i];     for (int i = 2; i <= n; i++)       for (int j = i; j <= n; j++) {         int x = a[i - 1] - 1, y = 0;         for (int k = i; k <= j; k++) {           int t = x / a[k];           y += t;           x -= t * a[k];         }         x = a[i - 1] - 1 - x + a[j];         y++;         if (x < ans) {           int o = x;           for (int k = 1; k <= n; k++) {             int t = x / a[k];             y -= t;             x -= t * a[k];           }           if (y < 0) ans = o;         }       }     if (ans == inf)       puts( -1 );     else       printf( %d n , ans);     return 0;   }   