from decimal import *
from sys import stdin, stdout
input = lambda: stdin.readline().rstrip()
write = stdout.write

def main():
    N = input()

    D = '0.1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991'
    getcontext().prec = 500
    ans = Decimal(D) * Decimal(N)
    print(ans)

main()