ChanParty

/*
    Task    : _example
    Author  : Phumipat C. [MAGCARI]
    Language: C++
    Created : 26 February 2023 [11:15]
*/
#include<bits/stdc++.h>
using namespace std;
struct A{
    int i,j,w;
    bool operator < (const A&o) const{
        return w>o.w;
    }
};
priority_queue<A > heap;
int a[1010][1010];
bool visited[1010][1010];
int dir[2][4] = {{1,-1,0,0},{0,0,1,-1}};
int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int q,n,sti,stj;
    long long m;
    cin >> q;
    while(q--){
        cin >> n >> m >> sti >> stj;
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                cin >> a[i][j];
        memset(visited,0,sizeof visited);
        heap.push({sti,stj,a[sti][stj]});
        visited[sti][stj] = true;
        long long cnt = 0;
        int mx = -1;
        while(!heap.empty()){
            A now = heap.top();
            heap.pop();
            cnt+=now.w;
            mx = max(mx,now.w);
            // visited[now.i][now.j] = true;
            if(cnt >= m){
                cout << mx << '\n';
                break;
            }
            for(int k=0;k<4;k++){
                int ni = now.i + dir[0][k],nj = now.j + dir[1][k];
                if(ni < 1 || nj < 1 || ni > n || nj > n)    continue;
                if(visited[ni][nj])                         continue;
                visited[ni][nj] = true;
                heap.push({ni,nj,a[ni][nj]});
            }
        }
        while(!heap.empty())    heap.pop();
    }
    return 0;
}