// Original C++ solution (slower):
#include<bits/stdc++.h>

#define mem0(a) memset(a,0,sizeof(a))  

#define meminf(a) memset(a,0x3f,sizeof(a))  

using namespace std;  

typedef long long ll;  

typedef long double ld;  

typedef double db;  

const int maxn=200005,inf=0x3f3f3f3f;    

const ll llinf=0x3f3f3f3f3f3f3f3f;     

const ld pi=acos(-1.0L);  

vector<int> v[maxn]; 

int main() {  

    int n,m,i,j,l,r;  

    scanf("%d%d",&n,&m);  

    priority_queue<int,vector<int>,greater<int> > pq;  

    for (i=1;i<=n;i++) {  

        scanf("%d%d",&l,&r);  

        if (l==0) pq.push(r); else v[l].push_back(r);  

    }  

    for (i=1;i<=m+1;i++) {  

        sort(v[i].begin(),v[i].end());  

    }  

    int pos=-1;  

    for (i=1;i<=m;i++) {

        if (v[i].size()>1) {

            for (j=0;j<v[i].size()-1;j++) pq.push(v[i][j]);  

        } else if (v[i].size()==0) {

            if (!pq.empty()) {

                if (pq.top()<=i) pq.pop(); else {  

                    pos=max(pos,i);  

                    while (!v[pos].size()&&pos<=m) pos++;  

                    if (v[pos].size()) v[pos].pop_back();  

                }    

            } else {

                pos=max(pos,i);

                while (!v[pos].size()&&pos<=m) pos++;

                if (v[pos].size()) v[pos].pop_back();

            }

        }

    }

    int ans=pq.size();

    printf("%d\n",ans); 

    return 0;

}

// Optimized solution to the same problem (faster):
#include <bits/stdc++.h>

using namespace std;

/*

Coded by 秦惜梦

The most attractive girl in the world

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*/



int n,m;



struct point{

	int l,r;

	void read(){

		scanf("%d%d",&l,&r);

	}

	bool operator<(const point &pt){

		return l<pt.l;

	}

};



point a[200005];



int main(){

	scanf("%d%d",&n,&m);

	for(int i=1;i<=n;i++){

		a[i].read();

	}

	sort(a+1,a+n+1);

	int l=1;

	priority_queue<int,vector<int>,greater<int> > pq;

	vector<int> rs;

	for(int i=1;i<=n;i++){

		pq.push(a[i].r);

		if(l<=m&&a[i].l>=l){

			l++;

		}else{

			rs.push_back(pq.top());

			pq.pop();

		}

	}

	sort(rs.begin(),rs.end());

	int r=m;

	int ans=0;

	for(int i=rs.size()-1;i>=0;i--){

		if(r>=l&&rs[i]<=r){

			r--;

		}else{

			ans++;

		}

	}

	printf("%d\n",ans);

	return 0;

}

// Fastest known solution for this problem: