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: Accepted)

function main(input) {
  let [a, b] = input[0].trim().split(" ").map(i => i);
  a = BigInt(parseInt(a));
  b = parseInt(b.split(".").join(""));
  ans = 0n;

  for(let i=0;i<b;i++){
    ans += a;
  }
  ans = ans + "";

  if(ans.length<=2){
    console.log(0);
  }else{
    const ans1 = ans.slice(0,ans.length-2);
    console.log(ans1);
  }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8').trim().split("\n"));