#include <stdio.h>

using namespace std;

#define maxn 400000

int N, M;
int arbore[maxn];
int start, finish, Val, Poz, maxim;

inline int max(int a, int b) 
{
       if ( a > b ) return a;
       return b;
}
 
void Update(int nod, int left, int right)
{
     if ( left == right )
     {
          arbore[nod] = Val;
          return;
     }
     
     int div = (left+right)/2;
     if ( Poz <= div ) Update(2*nod,left,div);
     else              Update(2*nod+1,div+1,right);
     
     arbore[nod] = max( arbore[2*nod], arbore[2*nod+1] );
}

void Query(int nod, int left, int right)
{
     if ( start <= left && right <= finish )
     {
          if ( maxim < arbore[nod] ) maxim = arbore[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(void)
{
    int X, A, B;
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    
    scanf("%d%d", &N, &M);
    for ( int i = 1; i <= N; i++ )
    {
        scanf("%d", &X);
        Poz = i, Val = X;
        Update(1,1,N);
    }   
    
    for ( int 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
        {
            Poz = A, Val = B;
            Update(1,1,N);
        }
    }
    fclose(stdin); fclose(stdout);
    return 0;
}