import decimal

A, B = input().split()

A = decimal.Decimal(A)

B = decimal.Decimal(B) * 100

print((decimal.Decimal(A * B // 100)))
A, B = input().split()

A = int(A)

B = round(float(B) * 100)

print((A * B // 100))

import decimal

A, B = input().split()
A = decimal.Decimal(A)
B = decimal.Decimal(B) * 100
print((decimal.Decimal(A * B // 100)))

A, B = input().split()
A = int(A)
B = round(float(B) * 100)
print((A * B // 100))

-import decimal - -A = decimal.Decimal(A) -B = decimal.Decimal(B) * 100 -print((decimal.Decimal(A * B // 100))) +A = int(A) +B = round(float(B) * 100) +print((A * B // 100))