#!/usr/bin/env perl

use strict;
use warnings;
use bignum;

my $d = 0.1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991;
my $n = <>;
chomp $n;

print $n * $d;