import math

a,b=[x for x in input().split()]

a=int(a)

b=round(float(b)*100)

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

a,b=[x for x in input().split()]

a=int(a)

b=round(float(b)*100)

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

a, b = [x for x in input().split()]
a = int(a)
b = round(float(b) * 100)
print((int(a * b // 100)))

import math

a, b = [x for x in input().split()]
a = int(a)
b = round(float(b) * 100)
print((a * b // 100))

-print((int(a * b // 100))) +print((a * b // 100))