#include <stdio.h>
#define max(a, b) a>b?a:b
#define log(x) 31-__builtin_clz(x)
#define N 1<<18

int n, seg[N];
void update (int i, int x) {
    i+=n-1;
    seg[i]=x;
    while (i>>=1)
        seg[i]=max(seg[i<<1], seg[(i<<1)+1]);
}

int query (int l, int r) {
    l+=n-1;
    r+=n-1;

    int ans=0;
    while (l<=r) {
        if (l&1) {
            ans=max(ans, seg[l]);
            ++l;
        }
        if (!(r&1)) {
            ans=max(ans, seg[r]);
            --r;
        }
        l>>=1;
        r>>=1;
    }
    return ans;
}

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

    int save, q, x, y, i;
    fscanf(fin, "%d%d", &n, &q);
    save=n;

    if (n&(n-1))
        n=1<<log(n)+1;

    for (i=1; i<=save; ++i) {
        fscanf(fin, "%d", &x);
        update(i, x);
    }

    int key;
    for (; q; q--) {
        fscanf(fin, "%d%d%d", &key, &x, &y);
        if (key)
            update(x, y);
        else
            fprintf(fout, "%d\n", query(x, y));
    }
    return 0;
}