Codeforces Round #313 A. Currency System in Geraldion

Description

A Magic Island Geraldion, where Gerald lives, have its own currency system. It uses banknotes of several values. But the problem is, the system isn't perfect and sometimes it happens that Geraldionians cannot express a certain sum of Money with any set of banknotes. Of course, they can use any number of banknotes for each value. Such sum is calledunfortunate. Gerald Wondered:what is the minimumunfortunate sum?

Input

The first line contains number n (1?≤? N. ≤?1000)-the number of values of the banknotes that used in geraldion.

The second line contains n distinct space-separated numbersa_{1,? A2,?...,? An} (1?≤? ) A_{i? ≤?10⁶})-the values of the banknotes.

Output

Print a single line-the minimum unfortunate sum. If There is no unfortunate sums, print?-? 1.

Sample Input

Input

51 2 3) 4 5

Output

-1

Test instructions: The smallest integer that cannot be made up of n integers, if all exist, output-1.

Train of thought: if n number has 1, then can compose, output-1, otherwise cannot compose the smallest integer digit 1, Output 1.

Code:

#include <cstdio>using namespace Std;int a[1010];int main () {    int n,flag=0;    while (scanf ("%d", &n)!=eof)   {    for (int i=0;i<n;i++)    scanf ("%d", &a[i]);    for (int i=0;i<n;i++)    {        if (a[i]==1)        {            flag=1;            break;        }    }    if (flag)    printf (" -1\n");    else        printf ("1\n");   }    return 0;}

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Codeforces Round #313 A. Currency System in Geraldion