#include using namespace std; struct BIT{ vector bit; BIT(int n) : bit(n, 0){} int range_sum(int i, int j) {return sum(j) - sum(i - 1);} // return sum of v[i] to v[j] including both ends. int sum(int j){ int s = 0; for (; j >= 0; j = (j & (j + 1)) - 1) s += bit[j]; return s; } void add(int k, int a) {for (; k < bit.size(); k |= k + 1) bit[k] += a;} }; int main(){ cin.tie(0); ios::sync_with_stdio(false); int N, M; cin >> N >> M; vector Es(M, -1); for (int i = 0; i < N; ++i){ int a, b; cin >> a >> b; if (a > b){ Es[b] = a; }else{ Es[a] = b; } } BIT bit(M); long long cnt = 0; for (int a = 0; a < M; ++a){ if (Es[a] == -1) continue; cnt += 1LL * bit.range_sum(a, Es[a]); bit.add(Es[a], 1); } cout << cnt << endl; return 0; }