from decimal import *



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



a = Decimal(str(a))

b = Decimal(str(b))

b *= Decimal(str(100))

ans = a * b

ans //= Decimal(str(100))



print(ans)

a, b = input().split()

a = int(a)

b = int(b.replace(".", ""))

ans = a * b // 100

print(ans)
from decimal import *

a, b = list(map(float, input().split()))
a = Decimal(str(a))
b = Decimal(str(b))
b *= Decimal(str(100))
ans = a * b
ans //= Decimal(str(100))
print(ans)

a, b = input().split()
a = int(a)
b = int(b.replace(".", ""))
ans = a * b // 100
print(ans)

-from decimal import * - -a, b = list(map(float, input().split())) -a = Decimal(str(a)) -b = Decimal(str(b)) -b *= Decimal(str(100)) -ans = a * b -ans //= Decimal(str(100)) +a, b = input().split() +a = int(a) +b = int(b.replace(".", "")) +ans = a * b // 100