import math
a,b = map(str, input().split())
b = b.replace(".","")
a = int(a)
b = int(b)
print(a * b // 100)
db32281b99795659c72c409c58e0454cd3e88a8d
<mask token>

<mask token>
print(a * b // 100)

<mask token>
a, b = map(str, input().split())
b = b.replace('.', '')
a = int(a)
b = int(b)
print(a * b // 100)

import math
a, b = map(str, input().split())
b = b.replace('.', '')
a = int(a)
b = int(b)
print(a * b // 100)

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