#include <stdio.h>
#include <fstream>
using namespace std;

#define in "arbint.in"
#define out "arbint.out"
#define dim 100001

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

int N, M, X, Y, tip, size, K;
int Arb[dim], A[dim];
int St[dim], Dr[dim];

void Update();
int Query();

int main()
{
    freopen(in,"r",stdin);
    freopen(out,"w",stdout);
    
    scanf("%d%d", &N, &M);
    for ( int i = 1; i <= N; i++ )
        scanf("%d", &A[i]);
    
    size=0;
    while ( size*size <= N ) size++;
    size--;
    
    K = N/size+1;
    
    for ( int i = 1; i*size <= N; i++ ) 
    {
        Arb[i] = -1;
        St[i] = size*(i-1)+1, Dr[i] = size*i;
        for ( int nod = St[i]; nod <= Dr[i]; nod++ )
            Arb[i] = Maxim(Arb[i],A[nod]);
    }
    
    for ( ; M; M-- )
    {
        scanf("%d%d%d", &tip, &X, &Y);
        
        if ( tip ) Update();
        else       printf("%d\n", Query());
    }
}

void Update()
{
     A[X] = Y;
     for ( int i = 1; i*size <= N; i++ )
         if ( X >= size*(i-1)+1 && X <= size*i )
         {
              Arb[i] = -1;
              for ( int nod = size*(i-1)+1; nod <= size*i; nod++ )
                  Arb[i] = Maxim(Arb[i],A[nod]);
              
              break;
         }
}

int Query()
{
    int maxim = -1;
    int st = (1<<30), dr=-1;
    
    for ( int i = 1; i <= K; i++ )
    {
        if ( X <= St[i] && Dr[i] <= Y )
        {
             if ( St[i] < st )  st = St[i];
             if ( Dr[i] > dr )  dr = Dr[i];
             maxim = Maxim(maxim,Arb[i]); 
        }
        if ( Dr[i] > Y ) break;
    }
    
    if ( st == (1<<30) && dr == -1 ) st = dr = Y;
    
    for ( int i = X; i <= st; i++ )
        maxim = Maxim(maxim,A[i]);
    
    for ( int i = dr; i <= Y; i++ )
        maxim = Maxim(maxim,A[i]);
    
    return maxim;
}