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 JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

const main = (input) => {
  const [a, b] = input.trim().split(' ')
  const _ans = (BigInt(a)*BigInt(parseInt(b*100, 10))).toString()

  return console.log(_ans.length > 2 ? _ans.slice(0, _ans.length-2) : 0)
}

process.env.MYTEST ? test() : main(require('fs').readFileSync('/dev/stdin', 'utf8'))