#line 2 "header.hpp"

//%snippet.set('header')%
//%snippet.fold()%
#ifndef HEADER_H
#define HEADER_H

// template version 2.0
#include <bits/stdc++.h>
using namespace std;

// varibable settings
template <class T> constexpr T inf = numeric_limits<T>::max() / 2.1;

#define _overload3(_1, _2, _3, name, ...) name
#define _rep(i, n) repi(i, 0, n)
#define repi(i, a, b) for (ll i = (ll)(a); i < (ll)(b); ++i)
#define rep(...) _overload3(__VA_ARGS__, repi, _rep, )(__VA_ARGS__)
#define _rrep(i, n) rrepi(i, 0, n)
#define rrepi(i, a, b) for (ll i = (ll)((b)-1); i >= (ll)(a); --i)
#define r_rep(...) _overload3(__VA_ARGS__, rrepi, _rrep, )(__VA_ARGS__)
#define each(i, a) for (auto &&i : a)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define pb(a) push_back(a)
#define mp(a, b) make_pair(a, b)
#define mt(...) make_tuple(__VA_ARGS__)
#define ub upper_bound
#define lb lower_bound
#define lpos(A, x) (lower_bound(all(A), x) - A.begin())
#define upos(A, x) (upper_bound(all(A), x) - A.begin())
template <class T, class U> inline void chmax(T &a, const U &b) { if ((a) < (b)) (a) = (b); }
template <class T, class U> inline void chmin(T &a, const U &b) { if ((a) > (b)) (a) = (b); }
template <typename X, typename T> auto make_table(X x, T a) { return vector<T>(x, a); }
template <typename X, typename Y, typename Z, typename... Zs> auto make_table(X x, Y y, Z z, Zs... zs) { auto cont = make_table(y, z, zs...); return vector<decltype(cont)>(x, cont); }

template <class T> T cdiv(T a, T b){ assert(a >= 0 && b > 0); return (a+b-1)/b; }

#define is_in(x, a, b) ((a) <= (x) && (x) < (b))
#define uni(x) sort(all(x)); x.erase(unique(all(x)), x.end())
#define slice(l, r) substr(l, r - l)

#include <cxxabi.h>
string demangle(const char * name) {
    size_t len = strlen(name) + 256;
    char output_buffer[len];
    int status = 0;
    return string(abi::__cxa_demangle(name, output_buffer, &len, &status));
}
template<class T> string type(T x){ return demangle(typeid(x).name()); }

typedef long long ll;
typedef long double ld;

template <typename T>
using PQ = priority_queue<T, vector<T>, greater<T>>;
void check_input() { assert(cin.eof() == 0); int tmp; cin >> tmp; assert(cin.eof() == 1); }

#if defined(PCM) || defined(LOCAL)
#else
#define dump(...) ;
#define dump_1d(...) ;
#define dump_2d(...) ;
#define cerrendl ;
#endif

#endif /* HEADER_H */
//%snippet.end()%
#line 2 "solve.cpp"
template<class T=ll> using vec = vector<T>;
struct Fast { Fast() { std::cin.tie(0); ios::sync_with_stdio(false); } } fast;

using vi = vector<int>;
using vvi = vector<vi>;
using pii = pair<int, int>;
using iii = tuple<int, int, int>;


int solve() {
    ll n,m;cin>>n>>m;
    vec<ll> b(n), c(n);
    map<ll, map<ll, ll>> d;
    rep(i, n){
        cin>>b[i]>>c[i];
        d[c[i]][b[i]]++;
    }

    ll ans = 0;
    rep(col, 1, n+1){
        ans += max(sz(d[col])-1, 0);
    }
    cout << ans << endl;
    return 0;
}


signed main(){/*{{{*/
    solve();

    #if defined(PCM) || defined(LOCAL)
    check_input();
    #endif

    return 0;
}/*}}}*/