Problem:
Score : 300 points

Problem Statement

Compute A \times B, truncate its fractional part, and print the result as an integer.

Constraints

0 \leq A \leq 10^{15}

0 \leq B < 10

A is an integer.

B is a number with two digits after the decimal point.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the answer as an integer.

Sample Input 1

198 1.10

Sample Output 1

217

We have 198 \times 1.10 = 217.8. After truncating the fractional part, we have the answer: 217.

Sample Input 2

1 0.01

Sample Output 2

0

Sample Input 3

1000000000000000 9.99

Sample Output 3

9990000000000000

Solution in Julia (1.4.0) (judge verdict: Accepted)

const double = Float64
const int = Int64

parseint(x) = parse(double, x)
readdouble() = map(parseint, split(readline()))

function main()
  a,b = split(readline()) 
  a = parse(int, a)
  b = parse(double,b)
  #println(a," ",b)
  ba = round(int,100b)
  #bb = floor(int,100b)-100ba
  println((a * ba)÷100)
  
end

main()