import math

import fractions

a, b = input().split()

a = int(a)

b = fractions.Fraction(b)

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

a, b = input().split()

a = int(a)

b = round(float(b) * 100)

print((a * b // 100))

import math
import fractions

a, b = input().split()
a = int(a)
b = fractions.Fraction(b)
print((math.floor(a * b)))

a, b = input().split()
a = int(a)
b = round(float(b) * 100)
print((a * b // 100))

-import math -import fractions - -b = fractions.Fraction(b) -print((math.floor(a * b))) +b = round(float(b) * 100) +print((a * b // 100))