#include<bits/stdc++.h>
using namespace std;

const int N = 505, LG = 10;
 
int st[N][N][LG][LG];
int a[N][N], lg2[N];

int yo(int x1, int y1, int x2, int y2) {
    x2++; y2++;
    int a = lg2[x2 - x1], b = lg2[y2 - y1];
    return max(
            max(st[x1][y1][a][b], st[x2 - (1 << a)][y1][a][b]),
            max(st[x1][y2 - (1 << b)][a][b], st[x2 - (1 << a)][y2 - (1 << b)][a][b])
            );
}
 
void build(int n, int m) { // 0 indexed
    for (int i = 2; i < N; i++) lg2[i] = lg2[i >> 1] + 1;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            st[i][j][0][0] = a[i][j];
        }
    }
    for (int a = 0; a < LG; a++) {
        for (int b = 0; b < LG; b++) {
            if (a + b == 0) continue;
            for (int i = 0; i + (1 << a) <= n; i++) {
                for (int j = 0; j + (1 << b) <= m; j++) {
                    if (!a) {
                        st[i][j][a][b] = max(st[i][j][a][b - 1], st[i][j + (1 << (b - 1))][a][b - 1]); 
                    } else {
                        st[i][j][a][b] = max(st[i][j][a - 1][b], st[i + (1 << (a - 1))][j][a - 1][b]);
                    } 
                }
            }
        }
    }
}

string s[N];
int l[N][N], u[N][N];

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, m; cin >> n >> m;
    for (int i = 0; i < n; i++) {
        cin >> s[i];
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (!j) l[i][j] = 1;
            else l[i][j] = 1 + (s[i][j - 1] <= s[i][j] ? l[i][j - 1] : 0);
        }
    }   
    for (int j = 0; j < m; j++) {
        for (int i = 0; i < n; i++) {
            if (!i) u[i][j] = 1;
            else u[i][j] = 1 + (s[i - 1][j] <= s[i][j] ? u[i - 1][j] : 0);
        }
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            int nw = 1, mnx = u[i][j], mny = l[i][j];
            for (int len = 1; len <= min(i, j); len++) {
                mnx = min(mnx, u[i][j - len]);
                mny = min(mny, l[i - len][j]);
                if (min(mnx, mny) >= len + 1) nw++;
                else break;
            }
            a[i][j] = nw;
        }
    }
    build(n, m);
    int q; cin >> q;
    while (q--) {
        int x1, y1, x2, y2; cin >> x1 >> y1 >> x2 >> y2;
        x1--, y1--; x2--; y2--;
        int l = 1, r = min(x2 - x1 + 1, y2 - y1 + 1), ans = 0;
        while (l <= r) {
            int mid = l + r >> 1;
            if (yo(x1 + mid - 1, y1 + mid - 1, x2, y2) >= mid) ans = mid, l = mid + 1;
            else r = mid - 1;
        }
        cout << ans << '\n';
    }
    return 0;
}