def c():

    from decimal import Decimal

    import math

    a, b = list(map(str, input().split()))

    print((int(math.floor(Decimal(a) * Decimal(b)))))



if __name__ == "__main__":

    c()

def cc():

    a, b = list(map(str, input().split()))

    a2 = int(a)

    b2 = int(b.replace('.', ''))

    c = a2 * b2

    ans = str(c)[0:-2] if len(str(c)) > 2 else 0

    print(ans)

if __name__ == "__main__":

    cc()

def c():
    from decimal import Decimal
    import math

    a, b = list(map(str, input().split()))
    print((int(math.floor(Decimal(a) * Decimal(b)))))


if __name__ == "__main__":
    c()

def cc():
    a, b = list(map(str, input().split()))
    a2 = int(a)
    b2 = int(b.replace(".", ""))
    c = a2 * b2
    ans = str(c)[0:-2] if len(str(c)) > 2 else 0
    print(ans)


if __name__ == "__main__":
    cc()

-def c(): -    from decimal import Decimal -    import math - +def cc(): -    print((int(math.floor(Decimal(a) * Decimal(b))))) +    a2 = int(a) +    b2 = int(b.replace(".", "")) +    c = a2 * b2 +    ans = str(c)[0:-2] if len(str(c)) > 2 else 0 +    print(ans) -    c() +    cc()