import decimal

A,B=input().split()

A=int(A)

B=decimal.Decimal(B)

print((int(A*B)))
A,B=input().split()

A=int(A)

bb=[str (c) for c in B]

flag=1

bb.remove(".")



b="".join(bb)



print((A*int(b)//100))
import decimal

A, B = input().split()
A = int(A)
B = decimal.Decimal(B)
print((int(A * B)))

A, B = input().split()
A = int(A)
bb = [str(c) for c in B]
flag = 1
bb.remove(".")
b = "".join(bb)
print((A * int(b) // 100))

-import decimal - -B = decimal.Decimal(B) -print((int(A * B))) +bb = [str(c) for c in B] +flag = 1 +bb.remove(".") +b = "".join(bb) +print((A * int(b) // 100))