#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------



int N,M;
vector<int> ev[602020];
int did[602020];

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	int ret=0;
	cin>>N>>M;
	FOR(i,N) {
		cin>>x>>y;
		x+=M;
		ev[y].push_back(x);
		ev[y+M].push_back(x+M);
	}
	
	multiset<int> ed;
	int ma=0;
	FOR(i,3*M) {
		FORR(e,ev[i]) ed.insert(e);
		while(ed.size() && *ed.begin()<i) ed.erase(ed.begin());
		
		if(i) did[i]=did[i-1];
		if(ed.size()) {
			did[i]++;
			ed.erase(ed.begin());
		}
		if(i>M) ma=max(ma,did[i]-did[i-M]);
	}
	
	cout<<N-ma<<endl;
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n';
	FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	solve(); return 0;
}
