#include<cstdio>
#include<fstream>
#define q 100001

using namespace std;

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

int Arbore[4*q],maxim,aux;

inline int max(int a, int b)
{
	if(a< b) return b;
		else return a;
}
inline void make(int left,int right,int nod,int pozitie,int elem)
{
	if(right==left)	
		{
			Arbore[nod]=elem;
			return;
		}
	
		int	mij=(right+left)/2;
			if(pozitie <= mij)	
			make(left,mij,2*nod,pozitie,elem);
			else
			make(mij+1,right,2*nod+1,pozitie,elem);
		
	Arbore[nod]=max(Arbore[2*nod],Arbore[2*nod+1]);
}

inline void interogare(int nod,int left, int right, int capat1, int capat2)
{
	if( left >= capat1 && right <= capat2)
	{
		if(maxim < Arbore[nod]) maxim=Arbore[nod];
		return;
	}
		int	mij=(left+right)/2;
			if(capat1<=mij) interogare(2*nod,left,mij,capat1,capat2);
			if(capat2>mij) interogare(2*nod+1,mij+1,right,capat1,capat2);
		
}
int main()
{
	int a,b,n,m,x;

	
	f >> n >> m;
	for(int i=1;i<=n;++i)
		{	
			f >> x;
		//	aux = x;
			make(1,n,1,i,x);
		}
	for(int i=1;i<=m;++i)
		{
			f >> x >> a >> b;
			if(x==1)
			{
				//aux=b;
				make(1,n,1,a,b);
			}
			else if(x==0)
			{
				maxim=-1;
				interogare(1,1,n,a,b);
				g << maxim << "\n";
			}
		}
		return 0;
	}