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#include <iostream>
#include <unordered_set>
#include <unordered_map>
#include <queue>

using namespace std;
typedef pair<int, int> i2;

struct hash_pair {
    size_t operator()(const i2 &p) const {
        auto hash1 = hash<int>{}(p.first);
        auto hash2 = hash<int>{}(p.second);
        return hash1 ^ hash2;
    }
};

unordered_set<i2, hash_pair> board;
unordered_set<i2, hash_pair> copy_board;

bool takeable(int x, int y, unordered_set<i2, hash_pair>& B) {
    return (B.count({x, y}) & (!B.count({x, y-1}) & !B.count({x, y+1}) | !B.count({x-1, y}) & !B.count({x+1, y})));
}

int solve() {
    
    queue<i2> q;
    copy_board = board;
    for(auto [x, y] : copy_board) {
        if(takeable(x, y, copy_board)) {
            q.push({x, y});
        }
    }
    int ans = 0;
    while(!q.empty()) {
        auto [x, y] = q.front();
        q.pop();
        if(copy_board.count({x, y})) {
            copy_board.erase({x, y});
            ans++;
            if(takeable(x-1, y, copy_board))
                q.push({x-1, y});
            if(takeable(x+1, y, copy_board))
                q.push({x+1, y});
            if(takeable(x, y-1, copy_board))
                q.push({x, y-1});
            if(takeable(x, y+1, copy_board))
                q.push({x, y+1});
        }
    }
    return ans;
}

int main() {

    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, m, k, q; cin >> n >> m >> k >> q;
    for(int i = 1; i <= k; ++i) {
        int x, y; cin >> x >> y;
        board.insert({x, y});
    }
    cout << solve() << "\n";
    while(q--) {
        int x, y; cin >> x >> y;
        if(board.count({x, y})) {
            board.erase({x, y});
        }
        else {
            board.insert({x, y});
        }
        cout << solve() << "\n";
    }
}