#include <fstream>
#include <vector>
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n, m, i, x, a, b;
bool op;
const int INF = 1e9;
vector <int> t;
void update (int p, int st, int dr, int poz, int val)
{
    if (st == dr)
    {
        t[p] = val;
        return;
    }
    int m = (st+dr)/2, ps = 2*p, pd = 2*p+1;
    if (poz <= m)
    {
        update(ps, st, m, poz, val);
    }
    else
    {
        update (pd, m+1, dr, poz, val);
    }
    t[p] = max (t[ps], t[pd]);
}
int query (int p, int st, int dr, int a, int b)
{
    if (a <= st && dr <= b)
        return t[p];
    int m = (st+dr)/2, ps = 2*p, pd = 2*p+1, rs = -INF, rd = -INF;
    if (a <= m)
        rs = query(ps, st, m, a, b);
    if (b >= m+1)
        rd = query(pd, m+1, dr, a, b);
    return max(rs, rd);
}
int main()
{
    fin >> n >> m;
    t.resize(4*n+1);
    for (i = 1; i <= n; i++)
    {
        fin >> x;
        update (1, 1, n, i, x);
    }
    for (int mc = 1; mc <= m; mc++)
    {
        fin >> op >> a >> b;
        if (op)
            update (1, 1, n, a, b);
        else
            fout << query (1, 1, n, a, b) << "\n";
    }
    return 0;
}