from decimal import Decimal

a, b = input().split()

a = int(a)

b = Decimal(b)

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

a = int(a)

b = int(float(b) * 100 + 0.5)

print((a * b // 100))
from decimal import Decimal

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

a, b = input().split()
a = int(a)
b = int(float(b) * 100 + 0.5)
print((a * b // 100))

-from decimal import Decimal - -b = Decimal(b) -print((int(a * b))) +b = int(float(b) * 100 + 0.5) +print((a * b // 100))