// Arbori de intervale.cpp : Defines the entry point for the console application.
//

#include <fstream>
///#include "stdafx.h"
using namespace std;

const int Max = 100001;

int N, M;
int Arbore[4 * Max + 66];
int start, finish, maximum, position, value;

inline int MAX(int a, int b) {
	if (a > b) return a;
	else return b;
}

void update(int nod, int left, int right) {
	if (left == right) {
		Arbore[nod] = value;
		return;
	}
	int middle = (left + right) / 2;
	if (position <= middle) update(2 * nod, left, middle);
	else update(2 * nod + 1, middle + 1, right);
	Arbore[nod] = MAX(Arbore[2 * nod], Arbore[2 * nod + 1]);
}

void query(int nod, int left, int right) {
	if (start <= left && right <= finish){
		if (maximum < Arbore[nod]) 
			maximum = Arbore[nod];
		return;
		}
	int middle = (left + right) / 2;
	if (start <= middle) query(2 * nod, left, middle);
	if (middle < finish) query(2 * nod + 1, middle + 1, right);
}

int main() {
	int X, A, B;
	ifstream fin("arbint.in");
	ofstream fout("arbint.out");

	fin >> N >> M;
	
	for (int i = 1; i <= N; ++i) {
		fin >> X;
		position = i, value = X;
		update(1, 1, N);
	}

	for (int i = 1; i <= M; ++i) {
		fin >> X >> A >> B;
		if (X == 0) {
			maximum = -1;
			start = A, finish = B;
			query(1, 1, N);
			fout << maximum << "\n";
		}
		else {
			position = A, value = B;
			update(1, 1, N);
		}
	}
	return 0;
}