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#include<bits/stdc++.h>
 
#define pb push_back
#define pob pop_back
#define eb emplace_back
#define fi first
#define se second
#define turbo ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define mid ((l+r)/2)
#define midLL ((l+r)/2LL)
#define mide ((lo+hi)/2)
#define mideLL ((lo+hi)/2LL)
#define endl '\n'
#define random_shuffle shandom_ruffle
#define lowbit(x) x&(-x)
#define bits(x) __builtin_popcount(x) 
#define mins(se) (*se.begin())
#define maxs(se) (*--se.end())
#define all(x) x.begin(), x.end()
#define log2_floor(i) (i ? __builtin_clzll(1) - __builtin_clzll(i) : -1)
#define siz(cont) ((int)cont.size())
#define each(it, cont) for(auto &it : cont)

using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;
using pli = std::pair<ll, int>;
using pil = std::pair<int, ll>;
using vll = std::vector<pll>;
using vii = std::vector<pii>;
using vi = std::vector<int>;
using vl = std::vector<ll>;
using vvl = std::vector<vl>;
using vvi = std::vector<vi>;
using vvii = std::vector<vii>;
using vli = std::vector<pli>;
using vvli = std::vector<vli>;
using vil = std::vector<pil>;
using vvil = std::vector<vil>;
using vc = std::vector<char>;
using vvc = std::vector<std::vector<char>>;
using vb = std::vector<bool>;
using vvb = std::vector<vb>;

void err() { std::cout << "\n"; fflush(stdout); }
template<class T, class... Ts>
void err(T arg, Ts &... args) {
    std::cout << arg << ' ';
    err(args...);
}

using namespace std;


int XX[] = {0, 1, -1, 0};
int YY[] = {1, 0, 0, -1};

vvi X({
    {-1, -1, 0},
    {-1, -1, 0},
    {1, 1, 0},
    {1, 1, 0}
});
vvi Y({
    {0, -1, -1},
    {0, 1, 1},
    {0, 1, 1},
    {0, -1, -1}
});

vvi A({
    {0, 0},
    {1, -1}
});
vvi B({
    {1, -1},
    {0, 0}
}); 

set<pii> brd;

int av = 0;

int n, m;

bool is_fr(int a, int b) {
    if (!brd.contains({a,b}))
        return false;
    for (int i = 0; i < 2; i++) {
        int ile = 0;
        for (int j = 0; j < 2; j++) {
            int aa = a+A[i][j];
            int bb = b+B[i][j];
            if (!brd.contains({aa, bb})) {
                ile++;
            }
        }
        if (ile == 2)
            return true;
    }
    return false;
}

int miel() {
    int res = 0;
    set<pii> save = brd;

    queue<pii> q;
    for (auto [a, b] : brd)
        if (is_fr(a, b))
            q.push({a, b});

    while (!q.empty()) {
        auto [a, b] = q.front();
        q.pop();
        if (!brd.contains({a, b}))
            continue;
        brd.erase({a, b});
        res++;

        for (int i = 0; i < 4; i++) {
            int aa = a+XX[i];
            int bb = b+YY[i];
            
            if (is_fr(aa, bb)) {
                q.push({aa, bb});
            }
        }
    }
    brd = save;
    return res;
}

signed main() { 
    turbo;
    int k, q;
    cin >> n >> m >> k >> q;
    while (k--) {
        int a, b; cin >> a >> b;
        brd.insert({a, b});
    }

    cout << miel() << endl;
    while (q--) {
        int a, b; cin >> a >> b;
        if (brd.contains({a, b}))
            brd.erase({a,b});
        else brd.insert({a,b});
        cout << miel() << endl;
    }
}