#include <bits/stdc++.h>   using namespace std;   double mn = 1e20, mx, t;   int n, low, high;   int main() {     cin >> n;     for (int i = 1; i <= n; i++) {       cin >> t;       mn = min(mn, (t + 1 - 1e-8) / i);       mx = max(mx, t / i);     }     n++;     low = (int)(n * mx + 1e-9), high = (int)(n * mn + 1 - 1e-9);     if (low + 1 == high)       cout <<  unique n  << low;     else       cout <<  not unique ;   }   