#include <iostream>
#include <algorithm>
using namespace std;
int read(){
	int re=0,c=getchar();
	while(c<'0'||c>'9') c=getchar();
	while(c>='0'&&c<='9') re=(re<<3)+(re<<1)+(c^48),c=getchar();
	return re;
}
const int maxn=3e5+5;
int n,a[maxn];
void init(){
	
}
void solve(){
	n=read();
	init();
	for (int i=1;i<=n;i++) a[i]=read();
	sort(a+1,a+n+1);
	int cs=0,ans=0;
	for (int i=n;i;i--){
		if(a[i]!=a[i+1]) cs++;
		if(i-1>=cs-1) ans=max(ans,n-i+1);
	}
	cout<<ans<<endl;
}
int main(){
	int t=read();
	while(t--) solve();
	return 0;
}