import math

x=input().split()

a=int(x[0])

b=int(x[1].replace('.',''))

c = int(a * b)

print((c//100))





x=input().split()

a=int(x[0])

b=int(x[1].replace('.',''))

print((a*b//100))
import math

x = input().split()
a = int(x[0])
b = int(x[1].replace(".", ""))
c = int(a * b)
print((c // 100))

x = input().split()
a = int(x[0])
b = int(x[1].replace(".", ""))
print((a * b // 100))

-import math - -c = int(a * b) -print((c // 100)) +print((a * b // 100))