#include<fstream> 
#include<algorithm>
#define DIM 400001

using namespace std; 

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

int MaxArb[DIM];
int N, M;
int maxim; 

void Update(int nod, int left, int right, int pos, int val) 
{
	if(left == right) 
	{
		MaxArb[nod] = val; 
		return; 
	}
	
	int div = (left + right)/2; 
	if(pos <= div) Update(2*nod,left,div,pos,val); 
	else           Update(2*nod+1,div+1,right,pos,val); 
	
	MaxArb[nod] = max(MaxArb[2*nod], MaxArb[2*nod+1]); 
	
}
void Query(int nod, int left, int right, int Start, int Finish) 
{
	if(Start <= left && right <= Finish) 
	{
		maxim = max(maxim, MaxArb[nod]); 
		return; 
	}
	
    int div = (left + right)/2;
	if(Start <= div)      Query(2*nod,left,div,Start,Finish); 
	else if(div < Finish) Query(2*nod+1,div+1,right,Start,Finish);
		
}
int main() 
{
	int X, A, B;
	
	in >> N >> M; 
	
	for(int i = 1; i <= N; i++) 
	{
		in >> X; 
		Update(1,1,N,i,X);
	}
	
	for(int i = 1; i <= M; i++) 
	{
		in >> X >> A >> B; 
		if(X == 0) 
		{
			maxim = -1;
			Query(1,1,N,A,B);
			out << maxim << '\n'; 
		}
		else
		{
			Update(1,1,N,A,B); 
		}
	}
	
	return 0; 
}