#include <cstdio>
FILE *f=fopen("arbint.in","r"),*g=fopen("arbint.out","w");
int n,m,st[400],dr[400],mx[400],a[100005],buc[100005],k;
void Read(); void Solve(); void Update(int x); void Query(int x,int y);
void Read()
{ int i,j,max1=0;
  fscanf(f,"%d %d",&n,&m);
   for(i=1;i<=n;i++) fscanf(f,"%d",&a[i]);
  k=1;
   while(k*k<=n) k++;
  k--;

   for(i=1;i<=k;i++)
    {st[i]=dr[i-1]+1; dr[i]=st[i]+k-1;
     max1=-1;
      for(j=st[i];j<=dr[i];j++)
       {if (a[j]>max1) max1=a[j];
       buc[j]=i;
       }
     mx[i]=max1;
    // cout<<st[i]<<" "<<dr[i]<<" "<<mx[i]<<"\n";
     }
}
void Solve()
{ int i,t,b,e;
  for(i=1;i<=m;i++)
  { fscanf(f,"%d",&t);
    if (!t) {fscanf(f,"%d %d",&b,&e); Query(b,e); }
     else {fscanf(f,"%d %d",&b,&e); a[b]=e; Update(b); }
  }
}
void Update(int x)
{ int i,v,max2;
  v=buc[x];
  if (!buc[x]) return;
  max2=-1;
  for(i=st[v];i<=dr[v];i++)
    if (a[i]>max2) max2=a[i];
  mx[v]=max2;
}
void Query(int x,int y)
{ int max3=-1,i,mnv=x,mxv=y;
    //cout<<mx[2]<<" "<<y<<" "<<st[buc[y]]<<" "<<dr[buc[y]]<<"\n";
    for(i=1;i<=k;i++)
    if (x<=st[i] && dr[i]<=y)
       { if (mx[i]>max3) max3=mx[i];
         if  (st[i]<mnv) mnv=st[i];
         if  (dr[i]>mxv) mxv=dr[i];
       }

    for(i=x;i<=mnv;i++) if (a[i]>max3) max3=a[i];
    for(i=mxv;i<=y;i++) if (a[i]>max3) max3=a[i];
fprintf(g,"%d\n",max3);
}
int main()
{ Read();
  Solve();
    return 0;
}