# BC program ternary
define mod3(n){
    auto r
    r=n%3
    if(r==2){
       r=-1
    }
    return(r)
}

# This gives the ternary expansion of n, where the digits are 0, 1 or -1.
define ternary(n,e){
    auto i,r,j
    i=0
  while(n){
    r=mod3(n)
    globalr[i]=r
    if(e){
       print r
    }
    n=(n-r)/3
    i=i+1
  }
  if(e){
     print "\n"
  }
  return(i)
}