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#include <bits/stdc++.h>
using namespace std;
int shiftx[4] = {1, -1, 0, 0};
int shifty[4] = {0, 0, 1, -1};
map<pair<int,int>, int>graph;
multiset<pair<int,int>>ms;
map<pair<int,int>, int>dp;
map<pair<int,int>, int>vis;
int c = 0;
bool upd;
void dpcalc(int x, int y){
    int updown = 0, leftright = 0;
    dp[{x,y}] = 2;
    for(int i = 0; i < 4; ++i){
        int dix = shiftx[i]+x, diy = shifty[i]+y;
        if(graph.find({dix,diy}) != graph.end()){
            int dpx = dp[{dix,diy}];
            if(dpx == 0){dpcalc(dix, diy); dpx = dp[{dix, diy}];}
            if(dpx == 1){
                if(i < 2) ++updown;
                else ++leftright;
            }
        }
        else{
            if(i < 2) ++updown;
            else ++leftright;
        }
    }
    if(updown == 2 or leftright == 2) {
        dp[{x,y}] = 1; 
        if(upd) ++c;
    }
}
int pass;
void dfs(int x, int y){
    if(dp[{x,y}] == 1) --c;
    dp[{x,y}] = 0;
    vis[{x,y}] = pass;
    for(int i = 0; i < 4; ++i){
        int dix = shiftx[i]+x; int diy = shifty[i]+y;
        if(graph.find({dix,diy}) != graph.end()){
            if(vis[{dix,diy}] != pass) dfs(dix, diy);
        }
    }
}
int cans(){
    int score = 0;
    for(pair<int,int>blocks : ms){
        if(dp[{blocks.first,blocks.second}] == 0) dpcalc(blocks.first, blocks.second);
        if(dp[{blocks.first,blocks.second}] == 1) ++score;
    }
    return score;
}
int main(){
    int n, m, k, q; cin >> n >> m >> k >> q;
    for(int i = 0; i < k; ++i){
        int x, y; cin >> x >> y;
        graph[{x,y}] = 1;
        ms.insert({x,y});
    }
    c = cans();
    cout << c << endl;
    upd = true;
    while(q--){
        ++pass;
        int x, y; cin >> x >> y;
        if(graph.find({x,y}) != graph.end()){
            graph.erase({x,y});
            ms.erase({x,y});
            if(dp[{x,y}] == 1){
                dp.erase({x,y});
                --c;
            }
            for(int i = 0; i < 4; ++i){
                int dix = shiftx[i]+x, diy = shifty[i]+y;
                if(graph.find({dix,diy}) != graph.end()){
                    if(vis[{dix,diy}] == pass) continue;
                    dfs(dix, diy);
                    dpcalc(dix,diy);
                }
            }
            cout << c << endl;
        }
        else{
            ms.insert({x,y});
            graph[{x,y}] = 1;
            dfs(x,y);
            dpcalc(x,y);
            cout << c << endl;
        }
    }
}