import decimal


def solve():
    decimal.getcontext().prec = 222
    d = decimal.Decimal('0.1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991')
    n = decimal.Decimal(input())

    ans = d * n
    print(ans)


if __name__ == '__main__':
    solve()