#include<bits/stdc++.h>
#define ll long long int
#define mp make_pair
#define ff first
#define ss second
#define pb push_back
#define ioS ios::sync_with_stdio(false);
 
const int sze=2e3+5;
const ll  mod=1e18;
using namespace std ;
ll  n,i,j,k,flag,sum,x,t,y,ans ;
 
ll a[2000008],b[2000008];
pair<ll,ll> p[200008] ;
 
int main(){
    ioS
cin >> t ;
while(t--){
 
map<ll,ll> m ;
map<ll,ll>::iterator itr ;
cin >> n ;
for(i=0;i<n;i++){cin >> a[i] ;  m[a[i]]++; }
itr = m.begin() ; k = 0 ; ans = 0 ;
while(itr!=m.end()){
    b[k] = itr->ss; itr++ ; k++ ;
}
 
sort(b,b+k) ;
j = b[(k-1)] ;
for(i=(k-2);i>=0;i--){
    ans += min(j,b[i]) ; j = abs(j-b[i]) ;
}
ans += j ;
cout << ans << endl ;
m.clear() ;
  }
 
}
 
 
 
 
 

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