from decimal import *

def solve():
    getcontext().prec = 450
    d = "0.1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991"
    s = input()
    print(Decimal(d) * Decimal(s))

if __name__=="__main__":
    solve()