#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    int n; cin >> n;
    int a[n] = {};
    rep(i,n) cin >> a[i];

    srep(i,1,101){
        int ng = 0;
        rep(j,n){
            int ok = 0;
            srep(k,1,i+1){
                if(k*100%i==0&&k*100/i==a[j]){
                    ok = 1;
                    break;
                }
            }
            if(ok == 0){
                ng = 1;
                break;
            }
        }
        if(ng == 0){
            cout << i << endl;
            return 0;
        }
    }
    cout << -1 << endl;
    return 0;
}