#include <fstream>
#include <vector>
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n, m, qi, i, x, y, t;
vector <int> aint;
void update (int s, int st, int dr, int pos, int val)
{
    if (st == dr)
    {
        aint[s] = val;
        return;
    }
    int m = (st+dr)/2, ps = 2*s, pd = 2*s+1;
    if (pos <= m)
        update (ps, st, m, pos, val);
    else
        update (pd, m+1, dr, pos, val);
    aint[s] = max (aint[ps], aint[pd]);
}
int query (int s, int st, int dr, int l, int r)
{
    if (l <= st && dr <= r)
        return aint[s];
    int m = (st+dr)/2, ps = 2*s, pd = 2*s+1, rs = -2e9, rd = -2e9;
    if (l <= m)
        rs = query (ps, st, m, l, r);
    else
        rd = query (pd, m+1, dr, l, r);
    return max (rs, rd);
}
int main()
{
    fin >> n >> m; aint.resize(4*n+1);
    for (i = 1; i <= n; i++)
    {
        fin >> x;
        update (1, 1, n, i, x);
    }
    for (qi = 1; qi <= m; qi++)
    {
        fin >> t >> x >> y;
        if (t == 1) update (1, 1, n, x, y);
        else fout << query(1, 1, n, x, y) << '\n';
    }
    return 0;
}