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

typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<pii> vpii;
typedef vector<string> vs;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef long double ld;
typedef unordered_map<int,int> umii;
typedef vector<pair<ll,ll>> vpll;
typedef tuple<int,int,int> tp;
typedef unsigned long long ull;
const ll mod=1e9+696969;

inline ll enc(int x,int y)
{
    return((ll)x<<20)|y;
}

struct b
{
    int x,y;
    bool c;
};

unordered_map<ll,b> brd;
int tot=0,cor=0;

bool qlf(ll k)
{
    if(brd.find(k)==brd.end())
    return 0;
    const b&blk=brd.at(k);
    bool h=0,v=0;
    if(brd.count(enc(blk.x,blk.y-1))and brd.at(enc(blk.x,blk.y-1)).c)
    h=1;
    if(brd.count(enc(blk.x,blk.y+1))and brd.at(enc(blk.x,blk.y+1)).c)
    h=1;
    if(brd.count(enc(blk.x-1,blk.y))and brd.at(enc(blk.x-1,blk.y)).c)
    v=1;
    if(brd.count(enc(blk.x+1,blk.y))and brd.at(enc(blk.x+1,blk.y)).c)
    v=1;
    return h and v;
}

void delupd(int x,int y)
{
    queue<ll> q;
    vpii d={{0,-1},{0,1},{-1,0},{1,0}};
    for(auto&p:d)
    {
        ll nk=enc(x+p.first,y+p.second);
        if(brd.count(nk)and brd[nk].c and!qlf(nk))q.push(nk);
    }
    while(!q.empty())
    {
        ll c=q.front();q.pop();
        if(!brd.count(c)or!brd[c].c or qlf(c))continue;
        brd[c].c=0;cor--;
        for(auto&p:d)
        {
            ll nn=enc(brd[c].x+p.first,brd[c].y+p.second);
            if(brd.count(nn)and brd[nn].c and!qlf(nn))
            q.push(nn);
        }
    }
}

void insupd(ll sk)
{
    vector<ll> cmp;
    queue<ll> q;
    unordered_set<ll> v;
    q.push(sk),v.insert(sk);
    while(!q.empty())
    {
        ll c=q.front();q.pop();
        cmp.push_back(c);
        for(auto n:{enc(brd[c].x,brd[c].y-1),enc(brd[c].x,brd[c].y+1),enc(brd[c].x-1,brd[c].y),enc(brd[c].x+1,brd[c].y)})
            if(brd.count(n)and!v.count(n))v.insert(n),q.push(n);
    }
    unordered_map<ll,pii> d;
    unordered_set<ll> inc;
    for(auto k:cmp)inc.insert(k);
    for(auto k:cmp)
    {
        b&blk=brd[k];
        int ch=inc.count(enc(blk.x,blk.y-1))+inc.count(enc(blk.x,blk.y+1));
        int cv=inc.count(enc(blk.x-1,blk.y))+inc.count(enc(blk.x+1,blk.y));
        d[k]={ch,cv};
    }
    queue<ll> p;
    unordered_set<ll> r;
    for(auto k:cmp)if(!d[k].first or!d[k].second)p.push(k),r.insert(k);
    while(!p.empty())
    {
        ll c=p.front();p.pop();
        for(auto n:{enc(brd[c].x,brd[c].y-1),enc(brd[c].x,brd[c].y+1),enc(brd[c].x-1,brd[c].y),enc(brd[c].x+1,brd[c].y)})
        {
            if(!inc.count(n)or r.count(n))
            continue;
            d[n].first-=(brd[n].x==brd[c].x);
            d[n].second-=(brd[n].y==brd[c].y);
            if(!d[n].first or!d[n].second)
            p.push(n),r.insert(n);
        }
    }
    for(auto k:cmp)
    {
        bool ns=!r.count(k);
        if(brd[k].c!=ns)
        cor+=(ns?1:-1),brd[k].c=ns;
    }
}

void ins(int x,int y)
{
    ll k=enc(x,y);
    brd[k]={x,y,0};
    tot++;
    insupd(k);
}

void del(int x,int y)
{
    ll k=enc(x,y);
    if(!brd.count(k))
    return;
    bool w=brd[k].c;
    brd.erase(k);
    tot--;
    if(w)cor--,delupd(x,y);
}

void solve()
{
    int n,m,k,q;
    cin>>n>>m>>k>>q;
    for(int i=0;i<k;i++)
    {
        int x,y;
        cin>>x>>y;
        brd[enc(x,y)]={x,y,0};
        tot++;
    }
    for(auto&e:brd)insupd(e.first);
    cout<<tot-cor<<"\n";
    while(q--)
    {
        int x,y;
        cin>>x>>y;
        ll k=enc(x,y);
        if(brd.count(k))del(x,y);
        else ins(x,y);
        cout<<tot-cor<<"\n";
    }
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    solve();
    return 0;
}