using namespace std;
#include<iostream>
#include<fstream>
#include<cstdlib>
#define oo 0x3f3f3f3f
int H[300000],a[100005],full[300000],N,M;
#define common int m=(l+r)/2,L=n*2,R=L+1

ofstream fout("arbint.out");

void update(int n,int ql,int qr,int l,int r,int v)
{
    if(ql<=l && qr<=r)
    {
        H[n]=v;
        full[n]=1;
        return;

    }
    int mij=(l+r)/2;
    int L=2*n;
    int R=L+1;

    if(full[n]==1)
    {
        full[n]=0;
        full[L]=full[R]=1;
        H[L]=H[R]=H[n];
    }

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

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

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

int query(int n,int ql,int qr,int l,int r)
{
    int x;
     if(full[n])
      return H[n];
     if(ql<=l && r<=qr)
      return H[n];
     int mij=(l+r)/2;
     int L=n*2;
     int R=L+1;
     int sol=-oo;

     if(ql<=mij)
     {
         x=query(L,ql,qr,l,mij);
         sol=sol>x?sol:x;

     }
    if(qr>=mij+1)
    {
        x=query(R,ql,qr,mij+1,r);
        sol=sol>x?sol:x;
    }
    return sol;
}

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

            int m=(l+r)>>1;
             int L=n<<1;
            int   R=L+1;
            build(L, l, m);
            build(R, m+1,r);

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

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

void cit()
{
    int x,i,xa,xb;
    ifstream fin("arbint.in");
fin>>N>>M;
for(i=1;i<=N;i++)
 fin>>a[i];
build(1,1,N);
int k=0;
 for(i=1;i<=M;i++)
   {fin>>x>>xa>>xb;
   if(x==1)
    {
    update(1,xa,xa,1,N,xb);


    }
    else


    fout<<query(1,xa,xb,1,N)<<"\n";}



fin.close();
fout.close();

}


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