#include <bits/stdc++.h>
using namespace std;

int main(){
    int n,h;cin>>n>>h;
    vector<pair<int,int>>time;
    for(int i=0;i<n;i++){
        int a,b;cin>>a>>b;
        time.push_back({a,1});
        time.push_back({b+1,0});
    }
    sort(time.begin(),time.end());
    int ans=0;
    int cnt=0;
    for(auto [i,j] :time){
        if(j==1){
            cnt++;
            ans=max(ans,cnt);
        }
        else{
            cnt--;
        }
    }
    cout<<ans<<endl;
}