from decimal import Decimal

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

b=100*b

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

a=int(a)

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

b=int(b)

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

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

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

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