#include <fstream>

using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");

int n,m,tree[4*100002+66],start,finish,val,pos,maxx;

void Update(int node,int left,int right)
{
    if(left==right)
    {
        tree[node]=val;
        return;
    }
    int div = (left+right)/2;
    if(pos<=div)
        Update(2*node,left,div);
    else
        Update(2*node+1,div+1,right);
    tree[node] = max(tree[2*node],tree[2*node+1]);
}

void Query(int node,int left,int right)
{
    if(start<=left && right<=finish)
    {
        if(maxx<tree[node])
            maxx=tree[node];
        return;
    }
    int div=(left+right)/2;
    if(start<=div)
        Query(2*node,left,div);
    if(div<finish)
        Query(2*node+1,div+1,right);
}

int main()
{
    int x,a,b;

    fin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        fin>>x;
        pos=i;
        val=x;
        Update(1,1,n);
    }
    for(int i=1;i<=m;i++)
    {
        fin>>x>>a>>b;
        if(x==0)
        {
            maxx = -1;
            start = a;
            finish = b;
            Query(1,1,n);

            fout<<maxx<<"\n";
        }
        else
        {
            pos=a;
            val=b;
            Update(1,1,n);
        }
    }
    return 0;
}