#include<bits/stdc++.h>
using namespace std;
const int MAXN = 300005;
int num[MAXN];
int number[MAXN];
struct Seg_Tre {int l, r;int w;
} tree[MAXN << 2];
inline void push_up(int x) {tree[x].w = max(tree[x << 1].w, tree[(x << 1) | 1].w);
}
inline void build(int x, int ll, int rr) {tree[x].l = ll, tree[x].r = rr;if (tree[x].l == tree[x].r) {tree[x].w = number[ll];return;}int m = (ll + rr) >> 1;build(x << 1, ll, m);build((x << 1 | 1), m + 1, rr);push_up(x);
}
inline void change_point(int x, int aim, int add) {if (tree[x].l == tree[x].r) {tree[x].w += add;return;}int m = (tree[x].l + tree[x].r) >> 1;if (aim <= m) {change_point(x << 1, aim, add);} else {change_point((x << 1) | 1, aim, add);}push_up(x);
}
inline int ask_interval(int x, int ll, int rr) {if (tree[x].l > rr || tree[x].r < ll)return -1;if (tree[x].l >= ll && tree[x].r <= rr) {return tree[x].w;}int now = 0;int m = (tree[x].l + tree[x].r) >> 1;if (ll <= m) {now = max(now, ask_interval(x << 1, ll, m));}if (rr > m) {now = max(now, ask_interval((x << 1) | 1, m + 1, rr));}return now;
}
vector<int> G[MAXN];
int main() {int n, r;int x, y;scanf("%d %d", &n, &r);for (int i = 1; i <= n; i++) {scanf("%d %d", &x, &y);G[x].push_back(y);num[y]++;}for (int i = 0; i <= 100000; i++) {for (int j = 0; j <= 2; j++) {if (i + j * r <= 100000) {number[i] += num[i + j * r];}}}build(1, 0, 100000);int ansnow = 0;for (int i = 0; i <= 100000; i++) {int now = 0;for (int j = 0; j <= 2; j++) {int u = i + j * r;if (u > 100000)break;for (int v : G[u]) {now++;for (int k = 0; k <= 2; k++)if (v - k * r >= 0)change_point(1, v - k * r, -1);}}ansnow = max(ansnow, now + ask_interval(1,0,100000));for (int j = 0; j <= 2; j++) {int u = i + j * r;if (u > 100000)break;for (int v : G[u]) {now++;for (int k = 0; k <= 2; k++)if (v - k * r >= 0)change_point(1, v - k * r, 1);}}}printf("%d\n", ansnow);return 0;
}