Table

/*
    Task    : Table
    Author  : Phumipat C. [MAGCARI]
    Language: C++
    Created : 22 January 2023 [08:56]
*/
#include<bits/stdc++.h>
using namespace std;
struct A{
    int val,i,j,time;
    bool operator < (const A&o) const{
        return val > o.val;
    }
};
priority_queue<A > heap;
int a[310][5010],lastEdit[310][5010];
int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int r,c,m;
    cin >> r >> c >> m;
    for(int i=1;i<=r;i++)
        for(int j=1;j<=c;j++)
            heap.push({0,i,j,0});
    for(int x=1;x<=m;x++){
        // x is current time
        int k;
        cin >> k;
        if(k == 1){
            int i,j,val;
            cin >> i >> j >> val;
            a[i][j] = val;
            lastEdit[i][j] = x;
            heap.push({val,i,j,x});
        }else if(k == 2){
            int i,val;
            cin >> i >> val;
            a[i][0] = val;
            lastEdit[i][0] = x;
            heap.push({val,i,0,x});
        }else if(k == 3){
            int i,j;
            cin >> i >> j;
            if(lastEdit[i][j] > lastEdit[i][0]) cout << a[i][j] << '\n';
            else                                cout << a[i][0] << '\n';
        }else if(k == 4){
            while(!heap.empty()){
                A now = heap.top();
                if(now.j != 0){
                    if(now.time < lastEdit[now.i][now.j] || now.time < lastEdit[now.i][0]){
                        heap.pop();
                        continue;
                    }
                    cout << now.val << '\n';
                    break;
                }else{
                    if(now.time < lastEdit[now.i][0]){
                        heap.pop();
                        continue;
                    }
                    int ch = 1;
                    for(int j=1;j<=c;j++){
                        if(lastEdit[now.i][j] < now.time){
                            cout << now.val << '\n';
                            ch = 0;
                            break;
                        }
                    }
                    if(ch)  heap.pop();
                    else    break;
                }
            }
        }
    }
    return 0;
}