Prase

#include <bits/stdc++.h>

using namespace std;

map<string, int> k;

int main(){

    int n, sum = 0, a = 0;
    cin >> n;

    for(int i=0; i<n; i++){
        string s;
        cin >> s;
        if(k[s]>sum-k[s]) a++;
        k[s]++; sum++;
    }

    cout << a;
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED