/**
*    author:  shu8Cream
*    created: 12.02.2021 21:19:22
**/

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i=0; i<(n); i++)
#define all(x) (x).begin(), (x).end()
using ll = long long;
using P = pair<int,int>;
using vi = vector<int>;
using vvi = vector<vi>;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n,m;
    cin >> n >> m;
    vi b(n),c(n),slime(n),bara;
    rep(i,n){
        cin >> b[i] >> c[i];
        slime[c[i]]++;
    }
    rep(i,n) if(slime[i]>1) bara.push_back(i);
    //rep(i,bara.size()) cout << bara[i] << endl;
    int ans = 0;
    rep(i,bara.size()){
        set<int> s;
        rep(j,n){
            if(c[j]==bara[i]) s.insert(b[j]);
        }
        ans+=s.size()-1;
    }
    cout << ans << endl;
}