#include <bits/stdc++.h>
using namespace std;
struct seg_tree{
struct node{
int val = 0;
int l, r;
};
vector<node> tree;
int n;
int dbInd = 0;
void build(int v){
if(v >= n){
tree[v].l = tree[v].r = dbInd++;
}else{
build(v*2); build(v*2+1);
tree[v].l = tree[v*2].l;
tree[v].r = tree[v*2+1].r;
}
}
seg_tree(int dd){
n = dd;
tree.resize(2 * n + 1);
build(1);
}
void change(int v, int l, int r, int x){
if(l <= tree[v].l && tree[v].r <= r){
tree[v].val += x;
}else if(tree[v].r < l || r < tree[v].l){
}else{
change(v*2, l, r, x);
change(v*2+1, l, r, x);
tree[v].val = tree[v*2].val + tree[v*2+1].val;
}
}
int find(int v, int l, int r){
if(l <= tree[v].l && tree[v].r <= r){
return tree[v].val;
}else if(tree[v].r < l || r < tree[v].l){
return 0;
}else{
return find(v*2, l, r) + find(v*2+1, l, r);
}
}
};
long long f1(vector<int> &mas, int X){ // N log N
// mas isrikiuotas
long long ret = 0;
for(auto x : mas){
// cout << x << " prd " << upper_bound(mas.begin(), mas.end(), x + X) - lower_bound(mas.begin(), mas.end(), x - X) << endl;
ret += upper_bound(mas.begin(), mas.end(), x + X) - lower_bound(mas.begin(), mas.end(), x - X)-1;
}
return ret;
}
long long f2(vector<pair<int, int> > &ms, int d){
const int dd = 150001;
vector<vector<int> > pts(dd);
vector<pair<int, int> > mas;
for(int i = 0; i < (int)ms.size(); i++){
int X = ms[i].first + ms[i].second;
int Y = ms[i].first - ms[i].second;
pts[X].push_back(Y);
}
seg_tree medis(dd * 2 + 10);
sort(mas.begin(), mas.end());
long long ans = 0;
for(int i = 0; i < dd; i++){
if(i-d-1 >= 0){
for(auto x : pts[i-d-1]){
//cout << "X = " << x << endl;
medis.change(1, x +dd, x + dd, -1);
}
}
sort(pts[i].begin(), pts[i].end());
for(int j = 0; j < (int)pts[i].size(); j++){
ans += upper_bound(pts[i].begin() + j, pts[i].end(), pts[i][j] + d) - pts[i].begin() - j -1;
//cout << "prd " << (int)( upper_bound(pts[i].begin() + j + 1, pts[i].end(), pts[i][j] + d) - pts[i].begin() - j - 2) << endl;
ans += medis.find(1, pts[i][j]-d + dd, pts[i][j]+d + dd);
}
for(auto x : pts[i]){
medis.change(1, x+dd, x + dd, 1);
}
}
return ans;
}
int main(){
int B, n, d, m; cin >> B >> n >> d >> m;
if(B == 1){
vector<int> ms(n); for(auto &x : ms) cin >> x;
sort(ms.begin(), ms.end());
cout << f1(ms, d) /2ll;
return 0;
}else if(B == 2){
vector<pair<int, int> > ms(n);
for(auto &x : ms) cin >> x.first >> x.second;
cout << f2(ms, d);
}
return 0;
}
