#include <fstream>

using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

int N, M;
int Aint[4 * 100005];
int A, B, val, poz, ans;

void Update(int nod, int st, int dr)
{
    if (st == dr)
    {
        Aint[nod] = val;
        return;
    }
    int mid = (st + dr) >> 1;
    if (poz <= mid)
        Update(nod << 1, st, mid);
    else
        Update((nod << 1) + 1, mid + 1, dr);
    Aint[nod] = max(Aint[nod << 1], Aint[(nod << 1) + 1]);
}
void Query(int nod, int st, int dr)
{
    if (A <= st && dr <= B)
    {
        ans = max(ans, Aint[nod]);
        return;
    }
    int mid = (st + dr) >> 1;
    if (A <= mid)
        Query(nod << 1, st, mid);
    if (B > mid)
        Query((nod << 1) + 1, mid + 1, dr);
}

int main()
{
    f >> N >> M;
    for (int i = 1; i <= N; ++i)
    {
        f >> val;
        poz = i;
        Update(1, 1, N);
    }
    for (int i = 1; i <= M; ++i)
    {
        int tip;
        f >> tip;
        if (tip == 0)
        {
            f >> A >> B;
            ans = -1;
            Query(1, 1, N);
            g << ans << "\n";
        }
        else
        {
            f >> poz >> val;
            Update(1, 1, N);
        }
    }
    f.close();
    g.close();
    return 0;
}