#include <cstdio>

using namespace std;

FILE *f, *g;

int n, q;

int rmq[502][502][10];

char s[6099];
int crChar;

int p2Max[502];

bool isDigit(char c)
{
    if(c >= '0' && c <= '9')
        return 1;

    return 0;
}

int getNr()
{
    int nr = 0;

    while(isDigit(s[crChar]))
    {
        nr = nr * 10 + s[crChar] - '0';

        crChar ++;
    }

    crChar ++;

    return nr;
}

void readFile()
{
    f = fopen("plantatie.in", "r");

    fscanf(f, "%d%d\n", &n, &q);

    int i, j;

    for(i = 1; i <= n; i ++)
    {
        fgets(s, 6000, f);
        crChar = 0;

        for(j = 1; j <= n; j ++)
            rmq[i][j][0] = getNr();
    }
}

void getP2Max()
{
    int i;

    p2Max[1] = 0;
    for(i = 2; i <= n; i ++)
        p2Max[i] = p2Max[i / 2] + 1;
}

inline int mxa(int a, int b)
{
    return (a > b ? a : b);
}

int mxa3(int a, int b, int c)
{
    if(a < b)
        return mxa(b, c);

    return mxa(a, c);
}

int mxa4(int a, int b, int c, int d)
{
    if(a < b)
        return mxa3(b, c, d);

    return mxa3(a, c, d);
}

void getRMQ()
{
    int j, i, h, p2;
    for(j = 1; (1 << j) <= n; j ++)
    {
        p2 = 1 << (j - 1);

        for(i = 1; i <= n - (1 << j) + 1; i ++)
        {
            for(h = 1; h <= n - (1 << j) + 1; h ++)
            {
                rmq[i][h][j] = mxa4(rmq[i][h][j - 1],
                                   rmq[i][h + p2][j - 1],
                                   rmq[i + p2][h][j - 1],
                                   rmq[i + p2][h + p2][j - 1]
                                   );
            }
        }
    }
}

void solve()
{
    getP2Max();

    getRMQ();
}

int poz(int a)
{
    if(a < 0)
        return (- a);

    return a;
}

void answerQuestions()
{
    g = fopen("plantatie.out", "w");

    int i, l, c, k, p2, difl, difc;
    for(i  = 1; i <= q; i ++)
    {
        fscanf(f, "%d%d%d", &l, &c, &k);

        p2 = p2Max[k];
        difl = k - (1 << p2);
        difc = k - (1 << p2);

        fprintf(g, "%d\n", mxa4(rmq[l][c][p2],
                                rmq[l + difl][c][p2],
                                rmq[l][c + difc][p2],
                                rmq[l + difl][c + difc][p2]));
    }
}

int main()
{
    readFile();

    solve();

    answerQuestions();

    return 0;
}