using namespace std;

#include<iostream>
#include<fstream>

#define common int L=2*n,R=L+1, m=(l+r)/2
#define oo 0x3f3f3f3f
#define nmax 100005

ofstream fout("arbint.out");

int H[3*nmax],full[3*nmax],a[nmax],N,M;
int query(int n,int l,int r,int ql,int qr)
{
    if(full[n]==1)
    {
      return H[n];
    }
    if(ql<=l && r<=qr)
    {
        return H[n];
    }

    common;

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

    }

    return sol;
}

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

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

}

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()
{
    ifstream fin("arbint.in");
    int i,x,y,z;
    fin>>N>>M;
    for(i=1;i<=N;i++)
      fin>>a[i];
    build(1,1,N);
    while(M--)
    {
        fin>>x>>y>>z;
        if(x==1)
          update(1,1,N,y,y,z);
        else
          fout<<query(1,1,N,y,z)<<"\n";
    }

    fin.close();
}

int main()
{

    cit();
    fout.close();
    return 0;
}