#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <functional>
#include <set>
#include <ctime>
#include <random>
#include <chrono>
#include <cassert>
#include <tuple>
#include <utility>
using namespace std;

namespace {
  using Integer = long long; //__int128;
  template<class T, class S> istream& operator >> (istream& is, pair<T,S>& p){return is >> p.first >> p.second;}
  template<class T> istream& operator >> (istream& is, vector<T>& vec){for(T& val: vec) is >> val; return is;}
  template<class T> istream& operator ,  (istream& is, T& val){ return is >> val;}
  template<class T, class S> ostream& operator << (ostream& os, const pair<T,S>& p){return os << p.first << " " << p.second;}
  template<class T> ostream& operator << (ostream& os, const vector<T>& vec){for(size_t i=0; i<vec.size(); i++) os << vec[i] << (i==vec.size()-1?"":" "); return os;}
  template<class T> ostream& operator ,  (ostream& os, const T& val){ return os << " " << val;}

  template<class H> void print(const H& head){ cout << head; }
  template<class H, class ... T> void print(const H& head, const T& ... tail){ cout << head << " "; print(tail...); }
  template<class ... T> void println(const T& ... values){ print(values...); cout << endl; }

  template<class H> void eprint(const H& head){ cerr << head; }
  template<class H, class ... T> void eprint(const H& head, const T& ... tail){ cerr << head << " "; eprint(tail...); }
  template<class ... T> void eprintln(const T& ... values){ eprint(values...); cerr << endl; }

  class range{ Integer start_, end_, step_; public: struct range_iterator{ Integer val, step_; range_iterator(Integer v, Integer step) : val(v), step_(step) {} Integer operator * (){return val;} void operator ++ (){val += step_;} bool operator != (range_iterator& x){return step_ > 0 ? val < x.val : val > x.val;} }; range(Integer len) : start_(0), end_(len), step_(1) {} range(Integer start, Integer end) : start_(start), end_(end), step_(1) {} range(Integer start, Integer end, Integer step) : start_(start), end_(end), step_(step) {} range_iterator begin(){ return range_iterator(start_, step_); } range_iterator   end(){ return range_iterator(  end_, step_); } };

  inline string operator "" _s (const char* str, size_t size){ return move(string(str)); }
  constexpr Integer my_pow(Integer x, Integer k, Integer z=1){return k==0 ? z : k==1 ? z*x : (k&1) ? my_pow(x*x,k>>1,z*x) : my_pow(x*x,k>>1,z);}
  constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z=1){return k==0 ? z%M : k==1 ? z*x%M : (k&1) ? my_pow_mod(x*x%M,k>>1,M,z*x%M) : my_pow_mod(x*x%M,k>>1,M,z);}
  constexpr unsigned long long operator "" _ten (unsigned long long value){ return my_pow(10,value); }

  inline int k_bit(Integer x, int k){return (x>>k)&1;} //0-indexed

  mt19937 mt(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count());

  template<class T> string join(const vector<T>& v, const string& sep){ stringstream ss; for(size_t i=0; i<v.size(); i++){ if(i>0) ss << sep; ss << v[i]; } return ss.str(); }

  inline string operator * (string s, int k){ string ret; while(k){ if(k&1) ret += s; s += s; k >>= 1; } return ret; }
}
constexpr long long mod = 9_ten + 7;

int main(){
  int n,m;
  cin >> n,m;
  vector<pair<int,int>> p(n);
  cin >> p;
  for(auto& pp : p){
    if( pp.first > pp.second ) swap(pp.first, pp.second);
  }
  sort(p.begin(), p.end());

  int blk_size = sqrt(m);
  int num_block = (m+blk_size-1)/blk_size;
  vector<vector<int>> b(num_block);
  for(int i=0; i<n; i++){
    b[p[i].first/blk_size].push_back( i );
  }
  for(int i=0; i<num_block; i++){
    sort(b[i].begin(), b[i].end(), [&](int a, int b){
      return p[a].second < p[b].second;
    });
  }

  vector<int> seg(m+1, -1);
  for(int i=0; i<p.size(); i++){
    seg[p[i].first] = i%n;
    seg[p[i].second] = i%n;
  }

  long long ans = 0;
  for(auto bb : b){
    vector<int> unko_set(n, 0);
    int cnt = 0;

    if(bb.size() == 0) continue;
    for(int i=p[bb[0]].first; i<=p[bb[0]].second; i++){
      if( seg[i] == -1 ) continue;
      if( unko_set[seg[i]] ){
        unko_set[seg[i]] ^= 1;
        cnt--;
      }else{
        unko_set[seg[i]] ^= 1;
        cnt++;
      }
    }
    ans += cnt;
    int l=p[bb[0]].first;
    int r=p[bb[0]].second;

    for(int i=1; i<bb.size(); i++){
      int j = bb[i];
      int ll = p[j].first;
      int rr = p[j].second;
      while(l>ll){
        l--;
        int k = seg[l];
        if( k != -1 ){
          if( unko_set[ k ] ){
            unko_set[k] ^= 1;
            cnt--;
          }else{
            unko_set[k] ^= 1;
            cnt++;
          }
        }
      }
      while(l<ll){
        int k = seg[l];
        if( k != -1 ){
          if( unko_set[ k ] ){
            unko_set[k] ^= 1;
            cnt--;
          }else{
            unko_set[k] ^= 1;
            cnt++;
          }
        }
        l++;
      }


      while(r<rr){
        r++;
        int k = seg[r];
        if( seg[k] != -1 ){
          if( unko_set[k] ){
            unko_set[k] ^= 1;
            cnt--;
          }else{
            unko_set[k] ^= 1;
            cnt++;
          }
        }
      }

      ans += cnt;
    }
  }
  
  println(ans/2);

  return 0;
}