#include <bits/stdc++.h>
using namespace std;
int main() {
int b, n, d, m;
cin >> b >> n >> d >> m;
if (b == 2) {
vector<pair<int, int>> vpi(n);
for (auto &[a, b] : vpi)
cin >> a >> b;
auto cmp = [&](pair<int, int> a, pair<int, int> b) {
return a.first - a.second < b.first - b.second;
};
sort(vpi.begin(), vpi.end(), cmp);
const int mn = 15e4;
struct nod {
int val;
nod *l, *r;
};
vector<nod *> vn;
function<nod *(int, int)> bui = [&](int cl, int cr) {
nod *n = new nod;
if (cl != cr) {
n->l = bui(cl, (cl + cr) / 2);
n->r = bui((cl + cr) / 2 + 1, cr);
}
return n;
};
vn.push_back(bui(0, mn));
function<nod *(nod *, int, int, int, int)> upd = [&](nod *cur, int l, int r,
int in, int val) {
nod *n = new nod;
if (l == r) {
n->val += val;
return n;
}
int mid = (l + r) / 2;
if (in <= mid) {
n->r = cur->r;
n->l = upd(cur->l, l, mid, in, val);
} else {
n->l = cur->l;
n->r = upd(cur->r, mid + 1, r, in, val);
}
n->val = n->l->val + n->r->val;
return n;
};
function<int(nod *, int, int, int, int)> qry = [&](nod *cur, int l, int r,
int ql, int qr) {
if (l > qr || r < ql)
return 0;
if (ql <= l && r <= qr) {
return cur->val;
}
return qry(cur->l, l, (l + r) / 2, ql, qr) +
qry(cur->r, (l + r) / 2 + 1, r, ql, qr);
};
for (auto [a, b] : vpi) {
// cout << a << " " << b << "\n";
vn.push_back(upd(vn.back(), 0, mn, a + b, 1));
}
// cout << "\n";
long long ans = 0;
for (auto [a, b] : vpi) {
int rt = upper_bound(vpi.begin(), vpi.end(), make_pair(a + d, b), cmp) -
vpi.begin(),
lt = lower_bound(vpi.begin(), vpi.end(), make_pair(a, b + d), cmp) -
vpi.begin();
// cout << lt << " " << rt << "\n";
ans += qry(vn[rt], 0, mn, a + b - d, a + b + d) -
qry(vn[lt], 0, mn, a + b - d, a + b + d);
// cout << ans << "\n";
}
cout << (ans - n) / 2 << "\n";
}
}
