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#include <cstdio>
#include <set>
#include <queue>
using namespace std;

void printp(long long i) {
    int x = (int)(i >> 32);
    int y = (int)i;
    printf("%d %d\n", x, y);
}

int main() {
    int n, m, k, q;
    set<long long> og_board;
    set<long long> board;
    scanf("%d%d%d%d", &n, &m, &k, &q);
    for (int i = 0; i < k; i++) {
        long long x, y;
        scanf("%lld%lld", &x, &y);
        og_board.insert((x << 32) + y);
    }
    for (int i = 0; i <= q; i++) {
        if (i != 0) {
            long long x, y;
            scanf("%lld%lld", &x, &y);
            long long v = (x << 32) + y;
            if (og_board.count(v) == 0) {
                og_board.insert(v);
                k++;
            }
            else {
                og_board.erase(v);
                k--;
            }
        }
        board = og_board;
        set<long long>::iterator it = board.begin();
        queue<long long> to_check;
        while (it != board.end()) {
            //printf("Entered "); printp(*it);
            to_check.push(*it);
            it++;
            while (!to_check.empty()) {
                long long cc = to_check.front();
                to_check.pop();
                //printf("started "); printp(cc);
                if (board.count(cc) == 0) continue;
                //printf("resolved "); printp(cc);
                if ((board.count(cc+1) == 0 && board.count(cc-1) == 0) || (board.count(cc+(1L << 32)) == 0 && board.count(cc-(1L << 32)) == 0)) {
                    if (*it == cc) it++;
                    board.erase(cc);
                    //printf("erased "); printp(cc);
                    if (board.count(cc+1) != 0) {
                        to_check.push(cc+1);
                        //printf("queued "); printp(cc+1);
                    }
                    if (board.count(cc-1) != 0) {
                        to_check.push(cc-1);
                        //printf("queued "); printp(cc-1);
                    }
                    if (board.count(cc+(1L<<32)) != 0) {
                        to_check.push(cc+(1L<<32));
                        //printf("queued "); printp(cc+(1L<<32));
                    }
                    if (board.count(cc-(1L<<32)) != 0) {
                        to_check.push(cc-(1L<<32));
                        //printf("queued "); printp(cc-(1L<<32));
                    }
                }
            }
        }
        int r = k - board.size();
        printf("%d\n", r);
    }
}