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


int n,m,start, finish, val, pos, maxim;
int maxarb[400070];

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);
    else 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,x;i<=n;i++)
    {
        scanf("%d",&x);
        pos=i;
        val=x;
        update(1,1,n);
    }
    for(int i=1,x,a,b;i<=m;i++)
    {
        scanf("%d%d%d",&x,&a,&b);
        if(!x)
        {
            maxim=-1;
            start=a;
            finish=b;
            query(1,1,n);
            printf("%d\n",maxim);
        }
        else
        {
            pos=a;
            val=b;
            update(1,1,n);
        }

    }
    return 0;
}