#include <stdio.h>
#define NMAX (1<<9)
#define MAX(a,b) (((a)>(b))?(a):(b))

int A[2*NMAX][2*NMAX], L1, L2, C1, C2, N, M, Vmax, Val;

void queryc(int,int,int,int);

void queryl(int p1, int p2, int nod)
{
        int mij = (p1+p2)>>1, x = nod<<1;

        if (L1<=p1 && p2<=L2)
        {
                queryc(0, NMAX-1, nod, 1);
                return;
        }
        if ((p1<=L1 && L1<=p2) || (p1<=L2 && L2<=p2))
        {
                queryl(p1, mij, x);
                queryl(mij+1, p2, x+1);
        }
}

void queryc(int p1, int p2, int nodx, int nod)
{
        int mij = (p1+p2)>>1, x = nod<<1;

        if (C1 <= p1 && p2 <= C2)
        {
                Vmax = MAX(Vmax, A[nodx][nod]);
                return;
        }
        if ((p1<=C1 && C1<=p2) || (p1<=C2 && C2<=p2))
        {
                queryc(p1, mij, nodx, x);
                queryc(mij+1, p2, nodx, x+1);
        }
}

void updatec(int,int,int);

void updatel(int l, int c)
{
        int nod = NMAX+l;

        updatec(l, c, nod);
        while (nod > 0)
        {
                nod = nod>>1;
                updatec(l, c, nod);
        }
}

void updatec(int l, int c, int nod)
{
        int nodc = NMAX+c, x;

        A[nod][nodc] = Val;
        while (nodc > 0)
        {
                nodc = nodc>>1;
                x = nodc<<1;
                A[nod][nodc] = A[nod][x];
                if (A[nod][nodc]<A[nod][x+1]) A[nod][nodc] = A[nod][x+1];
        }
}

int main()
{
        int i, j, c;
        
        freopen("plantatie.in", "r", stdin);
        scanf("%d%d", &N, &M);
        for (i = 0; i < N; i++)
            for (j = 0; j < N; j++)
            {
                scanf("%d", &Val);
                updatel(i,j);
            }

        freopen("plantatie.out", "w", stdout);
        if (M==0) printf("0\n");
        while (M--)
        {
                scanf("%d%d%d", &i, &j, &c); i--; j--;
                L1 = i; L2 = i+c-1; C1 = j; C2 = j+c-1; Vmax = -1;
                if (L2 >= N) L2 = N-1; if (C2 >= N) C2 = N-1;
                queryl(0, NMAX-1, 1);
                printf("%d\n", Vmax);
        }

        return 0;
        
}