#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
typedef long long ll;


int main()
{
  int T; cin>>T;
  FOR(t,0,T) {
    int N; cin>>N;
    vector<int> L(N);
    map<int, int> M;
    FOR(i,0,N) {
      cin>>L[i];
      M[L[i]]++;
    }
    int ans = 0;
    priority_queue<int> Q;
    for(auto x : M) Q.push(x.second);
    while(!Q.empty()) {
      int a = Q.top();Q.pop();
      if(Q.empty()) break;
      int b = Q.top();Q.pop();
      if(Q.empty()) break;
      int c = Q.top();Q.pop();
      ans += c;
      a -= c; b-= c; c = 0;
      if(a > 0) Q.push(a);
      if(b > 0) Q.push(b);
    }
    while(!Q.empty()) Q.pop();
    cout << ans << endl;
  }
}