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 Fortran (GNU Fortran 9.2.1) (judge verdict: Wrong Answer)

program c_
    use,intrinsic :: iso_fortran_env
    implicit none
    integer(int64):: a,b1,b2,b3
    real(real64):: b
    
    read*, a,b
    b1 = int(b)
    b2 = int(b*10)-b1*10
    b3 = int(b*100)-b2*10-b1*100
    print'(i0)', a*b1+a*b2/10+a*b3/100
end program c_