#include <cstdio>
#include<algorithm>
using namespace std;

int n,m,a,b,x;
int maxarb[400070];
int start, finish, val, pos, maxim;
void update(int nod, int left, int right)
{
     if ( left == right )
     {
          maxarb[nod] = val;
          return;
     }

     int mid = (left+right)/2;
     if ( pos <= mid ) update(2*nod,left,mid);
     else              update(2*nod+1,mid+1,right);

     maxarb[nod] = max( maxarb[2*nod], maxarb[2*nod+1] );
}

void query(int nod, int left, int right)
{
     if ( start <= left && right <= finish )
     {
          if ( maxim < maxarb[nod] ) maxim = maxarb[nod];
          return;
     }

     int mid = (left+right)/2;
     if ( start <= mid ) query(2*nod,left,mid);
     if ( mid < finish ) query(2*nod+1,mid+1,right);
}

int main()
{
    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);
        pos = 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
        {
            pos = a, val = b;
            update(1,1,n);
        }
    }
}