#include <fstream>

using namespace std;

int arbore[410000], N, M, X, a, b, start, sfarsit,pos, val, maxim;

void Update(int nod, int st, int dr)
{
    if (st == dr)
    {
        arbore[nod] = val;
        return;
    }
    int mij = (st + dr) / 2;
    if (pos <= mij)
        Update(2 * nod, st, mij);
    else
        Update(2 * nod + 1, mij + 1, dr);
    arbore[nod] = max(arbore[2 * nod], arbore[2 * nod + 1]);
}

void Query(int nod, int st, int dr)
{
    if (start <= st && dr <= sfarsit)
    {
        if (maxim < arbore[nod])
            maxim = arbore[nod];
        return;
    }
    int mij = (st + dr) / 2;
    if (start <= mij)
        Query(2 * nod, st, mij);
    if (mij < sfarsit)
        Query(2 * nod + 1, mij + 1, dr);
}

int main()
{
    ifstream f("arbint.in");
    ofstream o("arbint.out");
    f >> N >> M;
    for (int i = 1; i <= N; i++)
    {
        f >> X;
        pos = i;
        val = X;
        Update(1, 1, N);
    }

    for (int i = 1; i <= M; i++)
    {
        f >> X >> a >> b;
        if (X == 0)
        {
            maxim = -1;
            start = a;
            sfarsit = b;
            Query(1, 1, N);
            o << maxim << endl;
        }
        else
        {
            pos = a;
            val = b;
            Update(1, 1, N);
        }
    }
}