#include <fstream>

using namespace std;

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

int n, m;
int arb[400005];
int x, a, b;

void add (int node, int left, int right)
{
    if (left == right)
    {
        arb[node] = x;
        return;
    }
    int mid = left - (left - right) / 2;
    if (a <= mid)
        add (2 * node, left, mid);
    else
        add (2 * node + 1, mid+1, right);

    arb[node] = max (arb[2*node+1], arb[2*node]);
}

void query (int node, int left, int right)
{
    if (a <= left && right <= b)
    {
        x = max (arb[node], x);
        return ;
    }
    int mid = (left - ((left - right) / 2));
    if (a <= mid)
        query ( 2*node, left, mid);
    if (mid < b)
        query ( 2*node+1, mid+1, right);
}

int main ()
{
    fin >> n >> m;
    for (int i = 1; i <= n; ++ i)
    {
        a = i;
        fin >> x;
        add (1, 1, n);
    }
    for (int i = 0; i < m; ++i)
    {
        bool op;
        fin >> op;
        if (op)
        {
            fin >> a >> x;
            add (1, 1, n);
        }
        else
        {
            x = -1;
            fin >> a >> b;
            query (1, 1, n);
            fout << x << "\n";
        }
    }

    fin.close();
    fout.close();

    return 0;
}