#include <bits/stdc++.h>
#define f first
#define s second

using namespace std;
typedef pair <int, int> pii;

const int MAXN = 211111;
const double eps = 0.5;
vector <pii> a;
vector <int> tree[4 * MAXN];

void Merge(vector <int> & A, vector <int> & B, vector <int> & C){
    A.resize(B.size() + C.size());
    int i = 0, j = 0, ij = 0;
    while(i < B.size() && j < C.size()){
        if(B[i] < C[j])
            A[ij++] = B[i++];
        else
            A[ij++] = C[j++];
    }
    for(int k = i; k < B.size(); k++)
        A[ij++] = B[i];
    for(int k = j; k < C.size(); k++)
        A[ij++] = C[j];
}

void build(int tl, int tr, int v){
    if(tl == tr){
        tree[v].push_back(a[tl].s);
        return;
    }
    int mid = (tl + tr) >> 1;
    build(tl, mid, v << 1);
    build(mid + 1, tr, v << 1 | 1);
    Merge(tree[v], tree[v << 1], tree[v << 1 | 1]);
}

int query1(int tl, int tr, int v, int l, int r, double x){
    if(l > tr || r < tl)return 0;
    if(l <= tl && tr <= r){
        int cnt = lower_bound(tree[v].begin(), tree[v].end(), x) - tree[v].begin();
        return cnt;
    }
    int mid = (tl + tr) >> 1;
    return (query1(tl, mid, v << 1, l, r, x) + query1(mid + 1, tr, v << 1 | 1, l, r, x));
}

int query2(int tl, int tr, int v, int l, int r, double x){
    if(l > tr || r < tl)return 0;
    if(l <= tl && tr <= r){
        int cnt = upper_bound(tree[v].begin(), tree[v].end(), x) - tree[v].begin();
        return tree[v].size() - cnt;
    }
    int mid = (tl + tr) >> 1;
    return (query2(tl, mid, v << 1, l, r, x) + query2(mid + 1, tr, v << 1 | 1, l, r, x));
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, t;
    cin >> n >> t;
    a.resize(n);
    vector <int> tmp(n);
    for(int i = 0; i < n; i++){
        int l, r;
        cin >> l >> r;
        a[i] = {l, r};
        tmp[i] = l;
    }
    sort(a.begin(), a.end());
    sort(tmp.begin(), tmp.end());
    build(0, n - 1, 1);
    int ans = 0;
    for(int i = 0; i < n; i++){
        double cur_l = a[i].f, cur_r = cur_l + t - eps;
        int pos = lower_bound(tmp.begin(), tmp.end(), cur_l) - tmp.begin();
        ans = max(ans, query1(0, n - 1, 1, i, n - 1, cur_l + t - eps) - (i != 0 ? query2(0, n - 1, 1, 0, pos - 1, cur_l + t - eps): 0));
    }
    cout << ans << '\n';
    return 0;
}