$1=1
$2=4000000000

while$1<$2
$3=$1+$2
$3=$3+1
$3=$3/2
$5=K*4000000000
$4=$3+$5
$4=16000000000000000000/$4
if$3>$4
$2=$3
$2=$2-1
end
if$3<=$4
$1=$3
end
end
$4=$1*N
$4=$4/4000000000
$4=$4+N
return$4