from sys import stdin

from decimal import Decimal

import math

A, B = [Decimal(x) for x in stdin.readline().rstrip().split()]

print((int(math.floor(A * B))))
from sys import stdin

A,B=stdin.readline().rstrip().split()

print((int(A)*int(B.replace(".", ""))//100))
from sys import stdin
from decimal import Decimal
import math

A, B = [Decimal(x) for x in stdin.readline().rstrip().split()]
print((int(math.floor(A * B))))

from sys import stdin

A, B = stdin.readline().rstrip().split()
print((int(A) * int(B.replace(".", "")) // 100))

-from decimal import Decimal -import math -A, B = [Decimal(x) for x in stdin.readline().rstrip().split()] -print((int(math.floor(A * B)))) +A, B = stdin.readline().rstrip().split() +print((int(A) * int(B.replace(".", "")) // 100))