#有理数演算



from math import floor

from fractions import Fraction



a, b = input().split()

a = int(a)

b = Fraction(b)

print((floor(a * b)))
#正しい丸め処理



a, b = input().split()

a = int(a)

b = round(float(b) * 100)

print((a * b // 100))
# 有理数演算
from math import floor
from fractions import Fraction

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

# 正しい丸め処理
a, b = input().split()
a = int(a)
b = round(float(b) * 100)
print((a * b // 100))

-# 有理数演算 -from math import floor -from fractions import Fraction - +# 正しい丸め処理 -b = Fraction(b) -print((floor(a * b))) +b = round(float(b) * 100) +print((a * b // 100))