$0=N+1
$1=N/K
$2=N*N
$3=K*N
ifK==1
  $1=N*28657
  $1=$1/46368
end
ifK==2
  $1=N*19601
  $1=$1/47321
end
ifK==3
  $1=N*12970
  $1=$1/42837
end
while$0>$1
  $0=$1
  $4=$1*$1
  $1=2*$1
  $4=$4+$2
  $1=$1+$3
  $1=$4/$1
end
$0=$0+N
return$0