#include #include #include #include #include #include #include #include #include #include #include #include #pragma region using namespace std; #define FOR(i,r,n) for(ll i = (ll)(r); i < (ll)(n); i++) #define rep(i,n) FOR(i,0LL,n) #define RFOR(i,r,n) for(ll i=(ll)(n-1);i>=r;i--) #define rrep(i,n) RFOR(i,0LL,n) #define all(x) x.begin(),x.end() #define rall(x) x.rbegin(),x.rend() #define COUNT(a,y,x) upper_bound(all(a), y) - lower_bound(all(a), x) #define UNIQUE(a) sort(all(a)); a.erase(unique(all(a)), a.end()) #define SUM(a) accumulate(all(a),0LL) #define scan(x) scanf("%lld",&x) #define print(x) printf("%lld\n",x) #define print2(x) printf("%lld ",x) #define pb push_back typedef long long int ll; typedef vector vll; typedef vector vvll; typedef pair pll; typedef vector vpll; typedef vector vs; typedef map MAP; const ll inf = 2222222222222222222LL; const ll mod = 1000000007LL; ll n = 0, m = 0, ans = 0, cnt = 0, tmp = 0, ma = -inf, mi = inf; string s; bool ok = true, flag = false; ll dx[5] = { 1,-1,0,0,0 }, dy[5] = { 0,0,1,-1,0 }; ll ddx[9] = { 1,-1,0,0,1,1,-1,-1,0 }, ddy[9] = { 0,0,1,-1,1,-1,1,-1,0 }; #pragma endregion #define MAX 111111 struct BinaryIndexed { ll num; vll bit; BinaryIndexed(ll x = MAX) { num = x; bit.resize(x + 1, 0); } ll sum(ll i) { ll ret = 0; while (i > 0) { ret += bit[i]; i -= i & -i; } return ret; } void add(ll i, ll x) { if (i == 0) cout << "access 0 index" << endl; while (i <= num) { bit[i] += x; i += i & -i; } } }; ll x[MAX]; int main(void) { BinaryIndexed b; vpll v; cin >> n >> m; rep(i, n) { pll p; scan(tmp); p.first = tmp; scan(tmp); p.second = tmp; if (p.first > p.second) swap(p.first,p.second); v.pb(p); } sort(all(v)); ll cur = 0; rep(i, n) { FOR(j, cur, v[i].first) if (x[j]) b.add(j, -1); ans += b.sum(v[i].second); b.add(v[i].second, 1); x[v[i].second]++; cur = v[i].first; } cout << ans << endl; return 0; }