#include <cstdio>
#include <vector>
#include <queue>

FILE *fin, *fout;

#define MAXN 300
#define MAXQ 20000
#define MAXN_2 90000
#define MAXVAL 1000000

int N, Q;
int a[MAXN + 1][MAXN + 1];
int x1[MAXQ + 1], Y1[MAXQ + 1], x2[MAXQ + 1], y2[MAXQ + 1];
int st[MAXQ + 1], dr[MAXQ + 1], viz[MAXN + 1][MAXN + 1];
std::vector <int> check[MAXVAL + 1];

struct at {
	int x, y;
};

std::queue <at> q;

const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};

inline int maxi(int a, int b) {
	if (a > b)
		return a;
	return b;
}

inline bool bfs(int who, int limit) {
	if (a[x1[who]][Y1[who]] < limit || a[x2[who]][y2[who]] < limit)
		return 0;
	q = std::queue <at>();
	q.push({ x1[who], Y1[who] });
	memset(viz, 0, sizeof viz);
	viz[x1[who]][Y1[who]] = 1;
	while (!q.empty()) {
		at nod = q.front();
		q.pop();
		for (int j = 0; j < 4; j++) {
			int X = nod.x + dx[j], Y = nod.y + dy[j];
			if (viz[X][Y] == 0 && a[X][Y] >= limit) {
				viz[X][Y] = 1;
				q.push({ X, Y });
			}
			if (X == x2[who] && Y == y2[who])
				return 1;
		}
	}
	return 0;
}

int main() {
	fin = fopen("matrice2.in", "r");
	fout = fopen("matrice2.out", "w");
	fscanf(fin, "%d%d", &N, &Q);
	for(int i = 1;i <= N;i++)
		for (int j = 1; j <= N; j++) {
			fscanf(fin, "%d", &a[i][j]);
		}
	for (int i = 1; i <= Q; i++) {
		fscanf(fin, "%d%d%d%d", &x1[i], &Y1[i], &x2[i], &y2[i]);
		st[i] = 1, dr[i] = MAXVAL;
	}
	bool ok = 1;
	int pana;
	int pasi = 0;
	while (ok) {
		ok = 0;
		pana = 0;
		for (int i = 1; i <= Q; i++) {
			if (st[i] != dr[i]) {
				check[(st[i] + dr[i]) / 2].push_back(i), pana = maxi(pana, (st[i] + dr[i]) / 2);
			//	printf("%d  %d %d\n", i, st[i], dr[i]);
			}
		}
		for (int i = 1; i <= pana; i++) {//iau fiecare pas al cautarii binare
			while (check[i].size()) {
				ok = 1;
				int who = check[i].back();
				check[i].pop_back();
				bool ver = bfs(who, i);
				if (ver == 1) {
					st[who] = i + 1;
				}
				else
					dr[who] = i;
			}
		}
	}
	for (int i = 1; i <= Q; i++)
		fprintf(fout, "%d\n", st[i] - 1);
	fclose(fin);
	fclose(fout);
	return 0;
}