# include<bits/stdc++.h>
using namespace std;
int a[505][505],n,m,a1,b1,dx[4]={-1,1,0,0},dy[4]={0,0,-1,1},b[5000000],t1,r[505][505];
struct bad
{
	int x,y;
}f[10001];
struct good
{
	int x,y;
}g[10001];
struct point
{
	int x,y,t;
};
queue <point>q;
int main()
{
	cin>>n>>m>>a1>>b1;
	for(int i=1;i<=a1;i++)
	{
		cin>>f[i].x>>f[i].y;
		a[f[i].x][f[i].y]=1;
	}
	for(int i=1;i<=b1;i++)
	{
		cin>>g[i].x>>g[i].y;
		a[g[i].x][g[i].y]=2;
		r[g[i].x][g[i].y]=i;
	}
	/*for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=m;j++)
		{
			cout<<a[i][j]<<" ";
		}
		cout<<endl;
	}*/
	for(int i=1;i<=a1;i++)
	{
	point k={f[i].x,f[i].y,1};
	q.push(k);
    }
    int T;
    while(!q.empty())
    {
    	point l=q.front();
    	q.pop();
    	T=l.t;
    	//cout<<l.x<<" "<<l.y<<" "<<a[l.x][l.y]<<endl;
    	for(int i=0;i<4;i++)
    	{
    		int x0=l.x+dx[i],y0=l.y+dy[i];
    		if(x0<1||y0<1||x0>n||y0>m) continue;
    		if(a[x0][y0]==2)
    		{
    			b[r[x0][y0]]=l.t;
    			a[x0][y0]=1;
    			point h1={x0,y0,T+1};
    			q.push(h1);
			}
			if(a[x0][y0]==0)
			{
				//cout<<"789";
				a[x0][y0]=1;
    		    point h={x0,y0,T+1};
    		    q.push(h);
			}
		}
	}
	//cout<<t1<<endl;
	for(int i=1;i<=b1;i++)
	{
		cout<<b[i]<<endl;
	}
}