Table

/*
    Task    : _example
    Author  : Phumipat C. [MAGCARI]
    Language: C++
    Created : 18 January 2023 [19:45]
*/
#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],timeA[310][5010];
int main(){
    int r,c,m;
    scanf("%d %d %d",&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;
        scanf("%d",&k);
        if(k == 1){
            int i,j,v;
            scanf("%d %d %d",&i,&j,&v);
            a[i][j] = v;
            timeA[i][j] = x;
            heap.push({v,i,j,x});
        }else if(k == 2){
            int i,v;
            scanf("%d %d",&i,&v);
            a[i][0] = v;
            timeA[i][0] = x;
            heap.push({v,i,0,x});
        }else if(k == 3){
            int i,j;
            scanf("%d %d",&i,&j);
            if(timeA[i][j] >= timeA[i][0])
                printf("%d\n",a[i][j]);
            else
                printf("%d\n",a[i][0]);
        }else if(k == 4){
            while(!heap.empty()){
                A now = heap.top();
                if(now.j != 0){
                    if(now.time < timeA[now.i][now.j] || now.time < timeA[now.i][0]){
                        heap.pop();
                        continue;
                    }
                    printf("%d\n",now.val);
                    break;
                }else{
                    if(now.time < timeA[now.i][0]){
                        heap.pop();
                        continue;
                    }
                    int ch = 1;
                    for(int j=1;j<=c;j++){
                        if(timeA[now.i][j] < now.time){
                            printf("%d\n",now.val);
                            ch = 0;
                            break;
                        }
                    }
                    if(ch == 0) break;
                    else        heap.pop();
                }
            }
        }
    }
    return 0;
}