#include <bits/stdc++.h>
using namespace std;
 
int n, m;
int v[100005], arb[400005];
 
void build (int nod, int st, int dr)
{
    if (st == dr) {arb[nod] = v[st]; return;}
    int mij = (st+dr)/2;
    build(2*nod, st, mij);
    build(2*nod + 1, mij+1, dr);
    arb[nod] = max(arb[2*nod], arb[2*nod+1]);
}
 
void update(int nod, int st, int dr, int poz, int val)
{
    if (st == dr) {arb[nod] = val; return;}
    int mij = (st+dr)/2;
    if (poz > mij)
    {
        update(2*nod+1, mij+1, dr, poz, val);
    }
    else
    {
        update(2*nod, st, mij, poz, val);
    }
    arb[nod] = max(arb[2*nod], arb[2*nod+1]);
}
 
int query(int nod, int st, int dr, int l, int r)
{
    int maxi = 0;
    if (l <= st && dr <= r) {return arb[nod];}
    int mij = (st+dr)/2;
    if (mij >= l)
    {
        maxi = max(maxi, query(2*nod, st, mij, l, r));
    }
    if (mij + 1 <= r)
    {
        maxi = max(maxi, query(2*nod + 1, mij+1, dr, l, r));
    }
    return maxi;
}
 
int main()
{
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {cin >> v[i];}
    build(1, 1, n);
    for (int i = 1; i <= m; i++)
    {
        int type, st, dr, poz, val;
        cin >> type;
        if (type == 0)
        {
            cin >> st >> dr;
            cout << query(1, 1, n, st, dr) << '\n';
        }
        else
        {
            cin >> poz >> val;
            update(1, 1, n, poz, val);
        }
    }
 
    return 0;
}