#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <cfloat>
#include <ctime>
#include <cassert>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <numeric>
#include <list>
#include <iomanip>
#include <fstream>
   
using namespace std;
   

#define rep(i, n) for (int i = 0; i < (int)n; ++i)
#define foreach(it, c) for (__typeof__((c).begin()) it=(c).begin(); it != (c).end(); ++it)
#define rforeach(it, c) for (__typeof__((c).rbegin()) it=(c).rbegin(); it != (c).rend(); ++it)
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define CL(arr, val) memset(arr, val, sizeof(arr))
#define COPY(dest, src) memcpy(dest, src, sizeof(dest))
   
template <class T> void max_swap(T& a, const T& b) { a = max(a, b); }
template <class T> void min_swap(T& a, const T& b) { a = min(a, b); }

template <class T> void sort(vector<T>& c) { sort(c.begin(), c.end()); }
template <class T> void uniq(vector<T>& c) { sort(c.begin(), c.end()); c.erase(unique(c.begin(), c.end()), c.end()); }

template <class T> string to_s(const T& a) { ostringstream os; os << a; return os.str(); }
template <class T> T to_T(const string& s) { istringstream is(s); T res; is >> res; return res; }
  
bool valid(int x, int y, int w, int h) { return 0 <= x && x < w && 0 <= y && y < h; }

template <class T, class U> ostream& operator<<(ostream& os, pair<T, U>& p) { os << "( " << p.first << ", " << p.second << " )"; return os; }
  
template <class T> void print(T a, int n, const string& deli = " ", int br = 1) { for (int i = 0; i < n; ++i) { cout << a[i]; if (i + 1 != n) cout << deli; } while (br--) cout << endl; }
template <class T> void print(const T& c, const string& deli = " ", int br = 1) { foreach (it, c) { cout << *it; if (++it != c.end()) cout << deli;--it; } while (br--) cout << endl; }
template <class T> void print2d(T a, int w, int h, int width = -1, int br = 1) { for (int i = 0; i < h; ++i) { for (int j = 0; j < w; ++j) {    if (width != -1) cout.width(width); cout << a[i][j] << ' '; } cout << endl; } while (br--) cout << endl; }
   
template <class T> void input(T& a, int n) { for (int i = 0; i < n; ++i) cin >> a[i]; }
template <class T> void input(T* a, int n) { for (int i = 0; i < n; ++i) cin >> a[i]; }
template <class T> void input2d(T& a, int w, int h) { for (int i = 0; i < h; ++i) for (int j = 0; j < w; ++j) cin >> a[i][j]; }

void fast_io() { cin.tie(0); ios::sync_with_stdio(false); }
#define trace(x) (cout << #x << ": " << (x) << endl)

typedef long long ll;
typedef pair<int, int> pint;

const int dx[] = { 0, 1, 0, -1 };
const int dy[] = { 1, 0, -1, 0 };
  
const double PI = acos(-1.0);
const int mod = 1000000007;


const int INF = (1LL << 31) - 1;
int h, w;
// vector<vector<int> > g;
vector<int> g[1024];

// vector<vector<int> > data;
vector<int> data[2 * 1024];
int size(int n)
{
    int m = 1;
    while (m < n)
        m *= 2;
    return m;
}
void build_segtree()
{
    for (int i = 0; i < 2 * h - 1; ++i)
    {
        data[i].clear();
        data[i].resize(2 * w - 1, INF);
    }

    // x
    for (int y = 0; y < h; ++y)
    {
        const int i = y + (h - 1);

        for (int x = 0; x < w; ++x)
            data[i][x + (w - 1)] = g[y][x];

        for (int k = w - 2; k >= 0; --k)
            data[i][k] = min(data[i][2 * k + 1], data[i][2 * k + 2]);
    }

    // y
    for (int i = h - 2; i >= 0; --i)
        for (int j = 0; j < 2 * w - 1; ++j)
            data[i][j] = min(data[2 * i + 1][j], data[2 * i + 2][j]);
}
int x_query(int y_k, int x1, int x2, int k, int l, int r)
{
    if (x2 <= l || r <= x1)
        return INF;
    else if (x1 <= l && r <= x2)
        return data[y_k][k];

    int mid = (l + r) / 2;
    int lv = x_query(y_k, x1, x2, 2 * k + 1, l, mid);
    int rv = x_query(y_k, x1, x2, 2 * k + 2, mid, r);
    return min(lv, rv);
}
int y_query(int x1, int x2, int y1, int y2, int k, int l, int r)
{
    if (y2 <= l || r <= y1)
        return INF;
    else if (y1 <= l && r <= y2)
        return x_query(k, x1, x2, 0, 0, w);

    int mid = (l + r) / 2;
    int lv = y_query(x1, x2, y1, y2, 2 * k + 1, l, mid);
    int rv = y_query(x1, x2, y1, y2, 2 * k + 2, mid, r);
    return min(lv, rv);
}
int main()
{
    fast_io();

    int _h, _w, q;
    while (cin >> _h >> _w >> q, _h)
    {
        h = size(_h), w = size(_w);
        bool swawa = false;
        if (_h > _w)
        {
            swawa = true;
            swap(w, h);
        }
        for (int i = 0; i < h; ++i)
        {
            g[i].clear();
            g[i].resize(w, INF);
        }
        for (int y = 0; y < _h; ++y)
        {
            for (int x = 0; x < _w; ++x)
            {
                if (!swawa)
                    cin >> g[y][x];
                else
                    cin >> g[x][y];
            }
        }

        build_segtree();

        while (q--)
        {
            int y1, x1, y2, x2;
            cin >> y1 >> x1 >> y2 >> x2;
            ++x2, ++y2;
            if (swawa)
            {
                swap(x1, y1);
                swap(x2, y2);
            }
            cout << y_query(x1, x2, y1, y2, 0, 0, h) << endl;
        }
    }
}

Measured memory_bytes: 42992