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#include<iostream>
#include<vector>
#include<algorithm>
#include<utility>
#include<set>
#define ll long long

using namespace std;
set<pair<int,int>>s;
set<pair<int,int>>a;

int delete_turn(){
    int x,y;
    int cnt=0;
    set<pair<int,int>>temp;
    for(auto p : a){
        x=p.first;
        y=p.second;
        if((!a.count({x-1,y}) && !a.count({x+1,y}))||(!a.count({x,y-1}) && !a.count({x,y+1}))){
            //a.erase({x,y});
            temp.insert({x,y});
            ++cnt;
        }
    }
    for(auto p : temp){
        a.erase(p);
    }
    return cnt;
}

int solve(){
    
    int cur = delete_turn();
    int cnt = cur;
    while(cur!=0){
        cur=delete_turn();
        cnt+=cur;
    }
    return cnt;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);

    int n,m,k,q,x,y;
    cin>>n>>m>>k>>q;

    for(int i = 0;i<k;++i){
        cin>>x>>y;
        s.insert({x,y});
    }
    for(int Q = -1;Q<q;++Q){
        if(Q!=-1){
            cin>>x>>y;
            if(s.count({x,y})){
                s.erase({x,y});
            }
            else{
                s.insert({x,y});
            }
        }
        a=s;
        cout<<solve()<<"\n";

    }


    return 0;

}