#include using namespace std; typedef long long ll; typedef pair p_ll; template void debug(T itr1, T itr2) { auto now = itr1; while(now=0; i--) const ll MOD = pow(10,9)+7; const ll LLINF = pow(2,61)-1; const int INF = pow(2,30)-1; vector fac; void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; } ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; } ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; } ll gcd(ll a, ll b) { if (a pos; SegTree(ll N) { size = 1; while(size>=1) operate(x); } ll query(ll a, ll b) { ll L = 0, R = 0; for (a+=size, b+=size; a>=1, b>>=1) { if (a&1) { L = q(L,pos[a]); a++; } if (b&1) { b--; R = q(R,pos[b]); } } return q(L,R); } void operate(ll i) { pos[i] = pos[i*2] + pos[i*2+1]; } ll q(ll x, ll y) { return x + y; } }; // ---------------------------------------------------------------------- // ---------------------------------------------------------------------- int main() { ll N, M; cin >> N >> M; ll a[N], b[N]; rep(i,N) { cin >> a[i] >> b[i]; if (a[i]>b[i]) swap(a[i], b[i]); } ll act[M] = {}; rep(i,N) { act[a[i]] = b[i]; act[b[i]] = -1; } // debug(act, act+M); SegTree st(M); ll result = 0; rep(i,M) { if (act[i]==-1) st.update(act[i], st[act[i]]-1); else { result += st.query(i,act[i]+1); st.update(act[i], st[act[i]]+1); } } cout << result << endl; return 0; }