#include<stdio.h>
 
void nhapMang(int a[],int &n)
{
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		scanf("%d",&a[i]);
	}
}
 
int a[100000],b[100000000]={0};
main()
{
	int n,m,p;
	scanf("%d",&p);
	while(p--)
	{
		nhapMang(a,n);	
		for(int i=0;i<=n;i++)
		{
			b[a[i]]=0;
		}				
		for(int i=0;i<n;i++)
		{
			b[a[i]]++;
		}
		int tg=0;
		for(int i=0;i<n;i++)
		{
			if(b[a[i]]>1)
			{
				printf("%d\n",b[a[i]]);
				tg=1;
				break;
			}
		}
		if(tg==0)printf("NO\n");
	}
}

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