#include <fstream>
#pragma GCC optimize ("Ofast")

using namespace std;

ifstream fin ("arbint.in");
ofstream fout ("arbint.out");

int n, m, aint[500020], maxim, op, x, y;

int left_son(int nod)
{
    return 2*nod;
}

int right_son(int nod)
{
    return 2*nod+1;
}

void update(int nod, int st, int dr, int poz, int val)
{
    if(st==dr)
    {
        aint[nod]=val;
        return;
    }
    int mij = (st+dr)/2;
    if(poz<=mij)
        update(left_son(nod), st, mij, poz, val);
    else
        update(right_son(nod), mij+1, dr, poz, val);
    aint[nod]=max(aint[left_son(nod)], aint[right_son(nod)]);
}

void query (int nod, int st, int dr, int query_st, int query_dr)
{
    if(query_st <= st && dr <= query_dr)
    {
        maxim = max(maxim, aint[nod]);
        return;
    }
    int mij = (st+dr)/2;
    if(query_st <= mij)
        query(left_son(nod), st, mij, query_st, query_dr);
    if(mij+1 <= query_dr)
        query(right_son(nod), mij+1, dr, query_st, query_dr);
}
int main()
{
    fin>>n>>m;
    for(int i=1; i<=n; i++)
    {
        int x;
        fin>>x;
        update(1, 1, n, i, x);
    }
    while(m--)
    {
        fin>>op>>x>>y;
        maxim = -1;
        if(op==0)
        {
           query(1, 1, n, x, y);
           fout<<maxim<<'\n';
        }
        if(op==1)
            update(1, 1, n, x, y);
    }
    return 0;
}