#include"bits/stdc++.h" using namespace std; #define REP(k,m,n) for(int (k)=(m);(k)<(n);(k)++) #define rep(i,n) REP((i),0,(n)) using ll = long long; template class SegmentTree { private: using F = function; // モノイド型 int n; // 横幅 F f; // モノイド T e; // モノイド単位元 vector data; public: // init忘れに注意 SegmentTree() {} SegmentTree(F f, T e) :f(f), e(e) {} void init(int n_) { n = 1; while (n < n_)n <<= 1; data.assign(n << 1, e); } void build(const vector& v) { int n_ = v.size(); init(n_); rep(i, n_)data[n + i] = v[i]; for (int i = n - 1; i >= 0; i--) { data[i] = f(data[(i << 1) | 0], data[(i << 1) | 1]); } } void set_val(int idx, T val) { idx += n; data[idx] = val; while (idx >>= 1) { data[idx] = f(data[(idx << 1) | 0], data[(idx << 1) | 1]); } } T query(int a, int b) { // [a,b) T vl = e, vr = e; for (int l = a + n, r = b + n; l < r; l >>= 1, r >>= 1) { if (l & 1)vl = f(vl, data[l++]); // unknown if (r & 1)vr = f(data[--r], vr); // unknown } return f(vl, vr); } }; int main() { ll N, M; cin >> N >> M; vector> ab; rep(i, N) { ll a, b; cin >> a >> b; if (a > b)swap(a, b); ab.push_back({ a,b }); } sort(ab.begin(), ab.end()); auto f = [](ll a, ll b) {return a + b; }; SegmentTree seg(f, 0); seg.init(M); ll res = 0; for (auto& row : ab) { ll a, b; tie(a, b) = row; res += seg.query(a, b); seg.set_val(b, 1); } cout << res << endl; return 0; }