#include<stdio.h>
#define MAX(a,b) ((a)>(b) ? (a):(b))
int x,n,m,i,val,arb[500000],pos,max1,a,b,start,finish;
void up(int nod, int st, int dr)
{
    if(st==dr)
    {
        arb[nod]=val;
        return;
    }
    int mid=(st+dr)/2;
    if(pos<=mid)
        up(2*nod,st,mid);
    else
        up(2*nod+1,mid+1,dr);
    arb[nod]=MAX(arb[nod*2],arb[nod*2+1]);
}
void cauta(int nod, int st, int dr)
{
    if(start<=st && dr<=finish)
    {
        if(max1<arb[nod])
            max1=arb[nod];
        return;
    }
    int mij=(st+dr)/2;
    if(start<=mij)
        cauta(2*nod,st,mij);
    if(mij<finish)
        cauta(2*nod+1,mij+1,dr);
}
int main()
{
    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;
        up(1,1,n);
    }
    for(i=1;i<=m;i++)
    {
        scanf("%d %d %d",&x,&a,&b);
        if(!x)
        {
            max1=-1;
            start=a;
            finish=b;
            cauta(1,1,n);
            printf("%d\n",max1);
        }
        else
        {
            val=b;
            pos=a;
            up(1,1,n);
        }
    }
    return 0;
}