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

typedef struct
{
    int *tree;
    int size;
} segtree_t;

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

void segtree_build(segtree_t *st, int *arr, int node, int left, int right)
{
    if (left == right)
    {
        st->tree[node] = arr[left];
        return;
    }
    int mid = (left + right) / 2;
    segtree_build(st, arr, node * 2, left, mid);
    segtree_build(st, arr, node * 2 + 1, mid + 1, right);
    st->tree[node] = max(st->tree[node * 2], st->tree[node * 2 + 1]);
}

void segtree_update(segtree_t *st, int node, int left, int right, int index, int new_val)
{
    if (left == right)
    {
        st->tree[node] = new_val;
        return;
    }
    int mid = (left + right) / 2;
    if (index <= mid)
        segtree_update(st, node * 2, left, mid, index, new_val);
    else
        segtree_update(st, node * 2 + 1, mid + 1, right, index, new_val);

    st->tree[node] = max(st->tree[node * 2], st->tree[node * 2 + 1]);
}

int segtree_query(const segtree_t *st, int node, int left, int right, int q_left, int q_right)
{
    if (q_left <= left && right <= q_right)
        return st->tree[node];
    if (right < q_left || q_right < left)
        return 0;

    int mid = (left + right) / 2;
    int left_max = segtree_query(st, node * 2, left, mid, q_left, q_right);
    int right_max = segtree_query(st, node * 2 + 1, mid + 1, right, q_left, q_right);
    return max(left_max, right_max);
}

int main(void)
{
    FILE *fin = fopen("arbint.in", "r");
    FILE *fout = fopen("arbint.out", "w");

    int N, M;
    int *arr = NULL;
    segtree_t st;

    fscanf(fin, "%d %d", &N, &M);
    if ((arr = (int *)malloc((N + 1) * sizeof(arr))) == NULL)
    {
        perror(NULL);
        exit(-1);
    }
    for (int i = 1; i <= N; i++)
    {
        fscanf(fin, "%d", &arr[i]);
    }

    st.size = N;
    if ((st.tree = (int *)malloc(4 * N * sizeof(st.tree))) == NULL)
    {
        perror(NULL);
        exit(-1);
    }

    segtree_build(&st, arr, 1, 1, N);

    for (int op = 0; op < M; op++)
    {
        int type, a, b;
        fscanf(fin, "%d %d %d", &type, &a, &b);

        if (type == 0)
        {
            fprintf(fout, "%d\n", segtree_query(&st, 1, 1, N, a, b));
        }
        else
        {
            segtree_update(&st, 1, 1, N, a, b);
        }
    }

    fclose(fin);
    fclose(fout);
    free(st.tree);
    free(arr);
    return 0;
}