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

signed main(){
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n, m;
    cin >> m >> n;
    vector<int> start(n), fin(n);
    vector<pair<int,int>> w(m);
    for(int i = 0; i < m; i++){
        cin >> w[i].first >> w[i].second;
        w[i].first--;
        w[i].second--;
        start[w[i].first]++;
        fin[w[i].second]++;
    }
    int cur = 0;
    vector<int> res(n);
    for(int i = 0; i < n; i++){
        cur += start[i];
        res[i] = cur;
        cur -= fin[i];
    }
    /*for(auto it : res) cout << it << ' ';
    cout << '\n';*/
    vector<int> dpl(n, 1e9);
    vector<int> dpr(n, 1e9);
    vector<int> ansl(n);
    vector<int> ansr(n);
    ansl[0] = 1;
    dpl[0] = -1;
    dpl[1] = res[0];
    for(int i = 1; i < n; i++){
        int idl = upper_bound(dpl.begin(), dpl.end(), res[i]) - dpl.begin();
        dpl[idl] = res[i];
        ansl[i] = idl;
    }
    /*for(auto it : dpl) cout << it << ' ';
    cout << '\n';
    for(auto it : ansl) cout << it << ' ';*/
    ansr[n-1] = 1;
    dpr[1] = res[n-1];
    dpr[0] = -1;
    for(int i = n-2; i >= 0; i--){
        int idr = upper_bound(dpr.begin(), dpr.end(), res[i]) - dpr.begin();
        dpr[idr] = res[i];
        ansr[i] = idr;
    }
    /*cout << '\n';
    for(auto it : dpr) cout << it << ' ';
    cout << '\n';
    for(auto it : ansr) cout << it << ' ';*/
    int ans = 0;
    for(int i = 0; i < n; i++){
        ans = max(ans, ansl[i] + ansr[i] - 1);
    }
    cout << ans;
    return 0;
}