#include <fstream>

using namespace std;

const int lInt = 400500;

class TreeStructure
{
	int n, m;
	int ArbInt[lInt];

public :
	void Compute()	
	{
		ifstream inputFile("arbint.in");
		ofstream outputFile("arbint.out");

		inputFile >> n >> m;

		for(int x, i = 1; i <= n; ++i)	
		{
			inputFile >> x;

			UpdateTree(1, make_pair(1, n), i, x);
		}

		for(int type,x, y, i = 1; i <= m; ++i)	
		{
			inputFile >> type >> x >> y;

			if(type == 0)	{
				int solution = -1;
			
				Querry(1, make_pair(1, n), make_pair(x, y), &solution);

				outputFile << solution << '\n';
			}
			else	{

				UpdateTree(1, make_pair(1, n), x, y);
			}
		}

		outputFile.close();
		inputFile.close();
	}

	void UpdateTree(int nod, pair<int, int> extr, int idx, int x)
	{
		if(extr.first == extr.second)	{

			ArbInt[nod] = x;
			return;
		}

		int mid = (extr.first + extr.second) >> 1;

		if(idx <= mid)
			UpdateTree(2 * nod, make_pair(extr.first, mid), idx, x);
		else
			UpdateTree(2 * nod + 1, make_pair(mid + 1, extr.second), idx, x);

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

 	void Querry(int nod, pair < int , int > extr, pair < int, int > curInt, int *solution)
	{
		if(curInt.first <= extr.first && extr.second <= curInt.second)	{

			*solution = max(*solution, ArbInt[nod]);
			return;
		}

		int mid = (extr.first + extr.second) >> 1;
		
		if(curInt.first <= mid)
			Querry(2 * nod, make_pair(extr.first, mid), curInt, solution);
		if(mid < curInt.second)
			Querry(2 * nod + 1, make_pair(mid + 1, extr.second), curInt, solution);
	}
};

int main()
{
	TreeStructure xObj;

	xObj.Compute();

	return 0;
}