Unique Rows

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <map>

using namespace std;

map<vector<int>, int> rows;

int main() {
    int n, m;
    cin >> n >> m;

    for(int i = 0; i < n; i++) {
        vector<int> row(m);
        for(int i = 0; i < m; i++)
            cin >> row[i];
        rows[row]++;
    }
    int counter = 0;
    for(const auto& row : rows){
        if(row.second == 1)
            counter++;
    }
    cout << counter;
}