#include <stdio.h>
 
using namespace std;
int n,m;
long v[110000];
 
long maxim(int a,int b)
{
    long i,mx,aux;
    if (b<a){
                aux=a;
                a=b;
                b=aux;
            }
    mx=v[a];
    for(i=a+1;i<=b;i++)
        if (mx<v[i]) mx=v[i];
    return mx;
}
 
void inversare(int a,int b)
{
    v[a]=b;
}
int main()
{
    int i,op,a,b;
    FILE*f,*g;
    f=fopen("arbori.in","r");
    g=fopen("arbori.txt","w");
    fscanf(f,"%d%d",&n,&m);
    for(i=1;i<=n;i++)
        fscanf(f,"%ld",&v[i]);
    for(i=1;i<=m;i++)
    {
        fscanf(f,"%d",&op);
        fscanf(f,"%d",&a);
        fscanf(f,"%d",&b);
        switch(op)
        {
            case 0: {fprintf(g,"%f\n",maxim(a,b)); break;}
            case 1: {inversare(a,b); break;}
        }
    }
    return 0;
}