#include<bits/stdc++.h>
using namespace std;
const int N = 3360 + 5;
const int fx[] = {1, 0, 0, -1};
const int fy[] = {0, 1, -1, 0};
int n, m, bx, by;
int b[N][N];
struct Node {
	int x, y;
};
queue<Node> q;
int vis[N][N];
int use[N][N];
bool inmap(int nx, int ny) {
	return nx >= 1 && nx <= n && ny >= 1 && ny <= m;
}
int main() { 
	scanf("%d%d%d%d", &n, &m, &bx, &by);
	for (int i = 1; i <= bx; ++i) {
		int sx, sy;
		scanf("%d%d", &sx, &sy);
		q.push(Node{sx, sy});
		use[sx][sy] = 1;
	}
	for (int i = 1; i <= by; ++i)
		scanf("%d%d", &b[i][1], &b[i][2]);
	while (!q.empty()) {
		Node u = q.front();
		q.pop();
		for (int d = 0; d < 4; ++d) {
			int nx = u.x + fx[d];
			int ny = u.y + fy[d];
			if (inmap(nx, ny) && !use[nx][ny]) {
				vis[nx][ny] = vis[u.x][u.y] + 1;
				use[nx][ny] = 1;
				q.push(Node{nx, ny});
			}
		}
	}
	for (int i = 1; i <= by; ++i)
	    printf("%d\n", vis[b[i][1]][b[i][2]]);
	return 0;
}

Code