#include <stdio.h>
#include <fstream>
using namespace std;
int n, m;
int arbint[400067];
int start, finish, val, pos, maxim;
inline int max(int a, int b) {
       if ( a > b ) 
	    return a;
       return b;}
void Nod(int nod, int left, int right)
{if( left == right )
  {arbint[nod] = val;
  return;}
int div = (left+right)/2;
if ( pos <= div )
 Nod(2*nod,left,div);
else
  Nod(2*nod+1,div+1,right);     
arbint[nod] = max( arbint[2*nod], arbint[2*nod+1] );}
void Query(int nod, int left, int right)
{if ( start <= left && right <= finish )
   {if ( maxim < arbint[nod] ) maxim = arbint[nod];
          return;}  
int div = (left+right)/2;
if ( start <= div ) 
 Query(2*nod,left,div);
if ( div < finish ) 
 Query(2*nod+1,div+1,right);
}

int main()
{int x,a,b,i;
freopen("arbint.in","r",stdin);
freopen("arbint.out","w",stdout);
scanf("%d%d", &n, &m);
for(i = 1; i <= n; i++ )
   {scanf("%d", &x);
   pos=i;
   val=x;
   Nod(1,1,n);}   
    for(i=1;i<=m;i++)
    {scanf("%d%d%d", &x, &a, &b);
    if( x == 0 ) 
     {maxim = -1;
     start=a;
	 finish = b;
     Query(1,1,n);
     printf("%d\n", maxim);}
    else
     {pos = a;
	 val = b;
     Nod(1,1,n);}}}