B

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

int OPEN = 0;
int SHUT = 1;
int LEFT = 2;
int INSIDE = 3;
int RIGHT = 4;
int n, t;

struct comp {
    bool operator()(vector<int> const &a, vector<int> const &b) const {
        return a[0] < b[0];
    }
};

vector<vector<int> > kek;
vector<pair<int, int> > status;

string match(int i) {
    if (i == 2) return "LEFT";
    if (i == 3) return "INSIDE";
    else return "RIGHT";
}

void show() {
    for (int i = 0; i < n; i++) {
        cout << i << ' ' << match(status[i].first) << ' ' << match(status[i].second) << endl;
    }
}

signed main() {
    cin >> n >> t;
    for (int i = 0; i < n; i++) {
        int l, r;
        cin >> l >> r;
        vector<int> a(3);
        a[0] = l;
        a[1] = OPEN;
        a[2] = i;
        vector<int> b(3);
        b[0] = r;
        b[1] = SHUT;
        b[2] = i;
        kek.push_back(a);
        kek.push_back(b);
    }
    sort(kek.begin(), kek.end(), comp());
    status.resize(n, {RIGHT, RIGHT});
    int rep = 0;
    for (int l = 0, r = -1; l < kek.size(); l++) {
        int x = kek[l][0];
        while (r < kek.size() - 1 && kek[r + 1][0] - kek[l][0] < t) {
            r++;
            if (kek[r][1] == OPEN) {
                status[kek[r][2]].first = INSIDE;
            } else {
                status[kek[r][2]].second = INSIDE;
            }
        }
        int now = 0;
        for (int i = 0; i < n; i++) {
            if (status[i].first == INSIDE && status[i].second == INSIDE) {
                now++;
            } else if (status[i].first == LEFT && status[i].second == RIGHT) {
                now--;
            }
        }
        rep = max(rep, now);
        if (kek[l][1] == OPEN) {
            status[kek[l][2]].first = LEFT;
        } else {
            status[kek[l][2]].second = LEFT;
        }
    }
    cout << rep << endl;
    return 0;
}