#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

int a[100005];
int T,N;

int main()
{
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&N);
        for(int i=1;i<=N;i++)scanf("%d",&a[i]);
        
        int a0,a1;
        a0=a1=0;
        
        for(int i=1;i<=N;i++)
        {
            if(a[i]==0)a0=1;
            if(a[i]==1)a1=1;
        }
        
        if(a0*a1==1)printf("YES\n");
        else printf("NO\n");
    }
    
    return 0;
}