#include <stdio.h>
#include <stdlib.h>

#define N_MAX 400000

FILE *fin = NULL, *fout = NULL;
int tree[N_MAX];
int v[N_MAX];

int max(int a, int b)
{
    if (a > b)
        return a;
    else
        return b;
}

void build(int nod, int st, int dr)
{
    if (st == dr)
    {
        tree[nod] = v[st];
    }
    else
    {

        int mij = (st + dr) / 2;
        build(2 * nod, st, mij);
        build(2 * nod + 1, mij + 1, dr);

        tree[nod] = max(tree[2 * nod], tree[2 * nod + 1]);
    }
}

void update(int nod, int st, int dr, int pos, int val)
{
    if (st == dr)
    {
        tree[nod] = val;
    }
    else
    {
        int mij = (st + dr) / 2;

        if (pos <= mij)
            update(2 * nod, st, mij, pos, val);
        else
            update(2 * nod + 1, mij + 1, dr, pos, val);

        tree[nod] = max(tree[2 * nod], tree[2 * nod + 1]);
    }
}

void query(int nod, int st, int dr, int x, int y, int *ans)
{
    if (x <= st && dr <= y)
    {
        *ans = max(*ans, tree[nod]);
    }
    else
    {

        int mij = (st + dr) / 2;

        if (x <= mij)
            query(2 * nod, st, mij, x, y, ans);

        if (y > mij)
            query(2 * nod + 1, mij + 1, dr, x, y, ans);
    }
}

int main()
{

    int M, N, o, a, b, maxi;
    fin = fopen("arbint.in", "rt");
    fout = fopen("arbint.out", "wt");
    if (fin == NULL || fout == NULL)
        fscanf(fin, "%d %d", &N, &M);
    for (int i = 1; i <= N; ++i)
        fscanf(fin, "%d", &v[i]);
    build(1, 1, N);
    for (int i = 0; i < M; ++i)
    {
        fscanf(fin, "%d %d %d", &o, &a, &b);
        if (o == 0)
        {
            maxi = -1;
            query(1, 1, N, a, b, &maxi);
            fprintf(fout, "%d\n", maxi);
        }
        else
        {
            update(1, 1, N, a, b);
        }
    }

    return 0;
}