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#include <bits/stdc++.h>
using namespace std;

#define FOR(i,p,q) for(int i=(p); i<=(q); ++i)
#define ROF(i,p,q) for(int i=(p); i>=(q); --i)
#define REP(i,q) for(int i=0; i<(q); ++i)
#define pb push_back
#define as assign
#define rz resize
#define Co const
#define all(X) X.begin(), X.end()
#define rall(X) X.rbegin(), X.rend()
#define sz(X) (int)(X.size())
#define ckmax(a,b) a=max(a,b)
#define ckmin(a,b) a=min(a,b)
#define V vector
typedef long long ll;
typedef mt19937_64 mt;
#ifndef UNCLE
 typedef basic_string<bool> vb;
 typedef basic_string<int> vi;
 typedef basic_string<ll> vl;
#else
 typedef V<bool> vb;
 typedef V<int> vi;
 typedef V<ll> vl;
#endif

constexpr int MX_R=2e5+3,MX_C=2e5+3, MX_N=75e3+3,MX_Q=75e3+3, MX_M=MX_N+MX_Q;
int R,C,N,Q, M=0, res=0;
unordered_map<ll,int> ids;
struct EL{bool isOn; int up,rg,dw,lf;};
V<EL> els(MX_M,{0,0,0,0,0});
vi tmp;

void Dfs(int v){//zakladam ze isOn
    if(!els[els[v].up].isOn&&!els[els[v].dw].isOn){
        els[v].isOn=0,++res,tmp.pb(v);
        if(els[v].lf&&els[els[v].lf].isOn) Dfs(els[v].lf);
        if(els[v].rg&&els[els[v].rg].isOn) Dfs(els[v].rg);
    }else if(!els[els[v].lf].isOn&&!els[els[v].rg].isOn){
        els[v].isOn=0,++res,tmp.pb(v);
        if(els[v].up&&els[els[v].up].isOn) Dfs(els[v].up);
        if(els[v].dw&&els[els[v].dw].isOn) Dfs(els[v].dw);
    }
}
void Solv(){
    res=0;
    FOR(i,1,M) if(els[i].isOn) Dfs(i);
    while(!tmp.empty()) els[tmp.back()].isOn=1,tmp.pop_back();
    cout<<res<<"\n";
}
void Input(){
    cin>>R>>C>>N>>Q,R+=2,C+=2;
    ll r,c;
    auto Upt=[](Co ll v){
        if(ids.count(v)){//usuwanie
            els[ids[v]]={0,-1,-1,-1,-1}, ids.erase(v);
            if(ids.count(v-C)) els[ids[v-C]].dw=0;
            if(ids.count(v+1)) els[ids[v+1]].lf=0;
            if(ids.count(v+C)) els[ids[v+C]].up=0;
            if(ids.count(v-1)) els[ids[v-1]].rg=0;
        }else{
            ids[v]=++M, els[M].isOn=1;
            if(ids.count(v-C)) els[ids[v-C]].dw=M, els[M].up=ids[v-C];
            if(ids.count(v+1)) els[ids[v+1]].lf=M, els[M].rg=ids[v+1];
            if(ids.count(v+C)) els[ids[v+C]].up=M, els[M].dw=ids[v+C];
            if(ids.count(v-1)) els[ids[v-1]].rg=M, els[M].lf=ids[v-1];
        }
    };
    REP(_,N){
        cin>>r>>c;
        Upt(r*C+c);
    }
    Solv();
    REP(_,Q){
        cin>>r>>c;
        Upt(r*C+c);
        Solv();
    }
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);

    Input();
}