#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

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

int N, M;
int ArbInt[4 * 100001 + 66];
int start, finish, Val, Pos, m;

void Update(int nod, int left, int right, int Pos, int Val)
{
    if (left == right)
    {
        ArbInt[nod] = Val;
        return;
    }

    int mij = (left + right) / 2;
    if (Pos <= mij) 
        Update(2 * nod, left, mij, Pos, Val);
    else             
        Update(2 * nod + 1, mij + 1, right, Pos, Val);

    ArbInt[nod] = max(ArbInt[2 * nod], ArbInt[2 * nod + 1]);
}

void Query(int nod, int left, int right, int start, int finish)
{
    if (start <= left && right <= finish)
    {
        if (m < ArbInt[nod]) 
            m = ArbInt[nod];
        return;
    }

    int div = (left + right) / 2;
    if (start <= div) Query(2 * nod, left, div, start, finish);
    if (div < finish) Query(2 * nod + 1, div + 1, right, start, finish);
}


int main()
{
    int X, A, B;
	f >> N >> M;
    for (int i = 1; i <= N; i++)
    {
        f >> X; //citim valoarea
        Update(1, 1, N, i, X);
    }

    for (int i = 1; i <= M; i++)
    {
        f >> X >> A >> B; //citim operatia si valorile
        if (X == 0) //daca operatia e 0 trebuie sa cautam elementul maxim din intervalul [A,B]
        {
            m = -1;
            Query(1, 1, N, A, B);

            g << m << endl;
        }
        else //daca operatia e 1 trebuie sa schimbam valoarea de la indexul A cu valoarea de la indexul B
        {
            Pos = A;
            Val = B;
            Update(1, 1, N, A, B);
        }
    }
}