CF_560A_CurrencySystemInGeraldion

A. Currency System in Geraldion

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

A magic island Geraldion, where Gerald lives, has its own currency system. It uses banknotes of several values. But the problem is, the system is not 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 of 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 numbersa₁, a₂, ..., a_n (1 ≤ a_i ≤ 10⁶) — the values of the banknotes.

Output

Print a single line — the minimum unfortunate sum. If there are no unfortunate sums, print - 1.

Sample test(s)

Input

51 2 3 4 5

Output

-1

水题

但是还是木了下

两分钟的题十分钟才出代码

有1果断多少钱都凑得出

没1果断凑不出1

所以……

#include <iostream>#include <stdio.h>#include <algorithm>using namespace std;const int M=1005;int va[M];int main(){    int n;    scanf("%d",&n);    for(int i=0;i<n;i++)        scanf("%d",&va[i]);    sort(va,va+n);    if(va[0]==1)    {        printf("-1\n");        return 0;    }    else        printf("1\n");    return 0;}

排序也是误入歧途懒得改了

直接在输入的时候检查1就可以了……