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)

function Main(input) {
  input = input.replace(/\n/g, ' ');
  input = input.split(" ");
  var A = Number(input[0]);
  var B = input[1].split(".");
  var C = Number(B[0]);
  var D = Number(B[1]);
  var E = A*D;
  var F = (E.length<=2)?0:Number(String(E).slice(0,-2));
  var ans = A*C + F;
  console.log(Math.floor(ans));
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));