妈蛋wa了两次。。

时尚的定义是length大于1的要破个洞，一定要破个洞。。

According to rules of the Berland fashion, a jacket should be fastened by all the buttons except only one

#include <bits/stdc++.h>

using namespace std;

typedef __int64 LL;

const int N=1e3+10;

int a[N];

int n,sum;

int main()

{

    scanf("%d",&n);

    for(int i=1;i<=n;i++)

        scanf("%d",&a[i]);

    if(n==1)

    {

        if(a[1]==1)

            puts("YES");

        else

            puts("NO");

        return 0;

    }

    sum=0;

    for(int i=1;i<=n;i++)

        if(!a[i])

            sum++;

    if(sum!=1)

        puts("NO");

    else

        puts("YES");

    return 0;

}