using namespace std;
#include<iostream>
#include<fstream>
#define nmax 100005
#define  oo 0x3f3f3f3f
#define common int L=2*n,R=L+1,m=(l+r)/2
int H[3*nmax],full[3*nmax],a[nmax],N,M;

ofstream fout("arbint.out");
void update(int n,int l,int r,int ql,int qr,int v)
{
    if(ql<=l && r<=qr)
    {
        H[n]=v;
        full[n]=1;
        return;
    }

    common;

    if(full[n])
    {
        full[n]=0;
        full[L]=full[R]=0;
        H[L]=H[R]=H[n];
    }

    if(ql<=m)
       update(L,l,m,ql,qr,v);
    if(qr>=m+1)
       update(R,m+1,r,ql,qr,v);

    if(H[L]==H[R] && full[L] && full[R]) full[n]=1;
    else full[n]=0;

    H[n]=max(H[L],H[R]);

}


int query(int n,int l,int r,int ql,int qr)
{   int ans=-oo;
     if(full[n])
     {
         ans=max(ans,H[n]);
         return ans;
     }
    if(ql<=l && r<=qr)
    {
        ans=max(ans,H[n]);
        return ans;

    }

    common;
    int x;
    if(ql<=m)
    {
         x=query(L,l,m,ql,qr);
         ans=max(ans,x);
    }
    if(qr>=m+1)
    {
        x=query(R,m+1,r,ql,qr);
        ans=max(ans,x);
    }


    return ans;

}
void build(int n,int l,int r)
{
    if(l>=r) {H[n]=a[l]; full[n]=1; return;}

    common;

    build(L,l,m);
    build(R,m+1,r);

    if(H[L]==H[R] && full[L] && full[R]) full[n]=1;
    else full[n]=0;

    H[n]=max(H[L],H[R]);

}

void cit()
{ int i,j,op,x,y;
    ifstream fin("arbint.in");

    fin>>N>>M;
    for(i=1;i<=N;i++)
    {
        fin>>a[i];
    }
    build(1,1,N);

    for(i=1;i<=M;i++)
    {
        fin>>op>>x>>y;
        if(op==1)
           update(1,1,N,x,x,y);
           else
           fout<<query(1,1,N,x,y)<<"\n";
    }
    fin.close();
}

int main()
{
    cit();
    fout.close();
    return 0;
}