#include <bits/stdc++.h>
using namespace std;
ifstream f("arbint.in");
ofstream g("arbint.out");
// #define f cin
// #define g cout
class ST
{
    int n, size = 1;
    vector<int> v;
    void build(int ac, int st, int dr)
    {
        if (dr - st == 1)
            if (st < n)
                f >> v[ac];
            else
                v[ac] = -1;
        else
        {
            int mid = (st + dr) >> 1;
            build((ac << 1) + 1, st, mid);
            build((ac << 1) + 2, mid, dr);
            v[ac] = max(v[(ac << 1) + 1], v[(ac << 1) + 2]);
        }
    }
    void update(int ac, int st, int dr, int poz, int nr)
    {
        if (dr - st == 1)
            v[ac] = nr;
        else
        {
            int mid = (st + dr) >> 1;
            if (poz < mid)
                update((ac << 1) + 1, st, mid, poz, nr);
            else
                update((ac << 1) + 2, mid, dr, poz, nr);
            v[ac] = max(v[(ac << 1) + 1], v[(ac << 1) + 2]);
        }
    }
    int query(int ac, int st, int dr, int l, int r)
    {
        if (st >= r || dr <= l)
            return -1;
        if (st >= l && dr <= r)
            return v[ac];
        int mid = (st + dr) >> 1;
        int m1 = query((ac << 1) + 1, st, mid, l, r);
        int m2 = query((ac << 1) + 2, mid, dr, l, r);
        return max(m1, m2);
    }

public:
    void build(int n)
    {
        this->n = n;
        while (size < n)
            size <<= 1;
        v.resize((size << 1) - 1);
        build(0, 0, size);
    }
    void update(int poz, int nr)
    {
        update(0, 0, size, poz, nr);
    }
    int query(int st, int dr)
    {
        return query(0, 0, size, st, dr);
    }
} aint;
int main()
{
    ios_base::sync_with_stdio(false);
    f.tie(nullptr);
    g.tie(nullptr);
    int n, q;
    f >> n >> q;
    aint.build(n);
    for (int a, b, c; q; q--)
    {
        f >> c >> a >> b;
        if (c)
            aint.update(a - 1, b);
        else
            g << aint.query(a - 1, b) << '\n';
    }
    return 0;
}