#include <stdio.h>
#include <math.h>
#define N 1<<18

int n, q, tree[N];
static inline int max (const int a, const int b) {
    return a>b?a:b;
}

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

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

int main () {
    FILE *fin=fopen("arbint.in", "r"),
         *fout=fopen("arbint.out", "w");
    fscanf(fin, "%d%d", &n, &q);
    int i, lg=log2(n), save=n, x, key, a, b;
    if (1<<lg!=n)
        n=1<<lg+1;
    for (i=1; i<=save; i++) {
        fscanf(fin, "%d", &x);
        update(i, x);
    }
    for (; q; q--) {
        fscanf(fin, "%d%d%d", &key, &a, &b);
        if (key)
            update(a, b);
        else
            fprintf(fout, "%d\n", query(a, b));
    }
    return 0;
}