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)

"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const A = BigInt(arg[0].split(" ")[0]);
    const B = BigInt(arg[0].split(" ")[1].split(".").join(""));

    // const J  = BigInt(B.split(".")[0]);
    // const S1 = BigInt(B.split(".")[1].split("")[0]);
    // const S2 = BigInt(B.split(".")[1].split("")[1]);
    
    // let answer = (A * J) + ((A * S1) / 10n) + ((A * S2) / 100n);
    
    let answer = A * BigInt(B);
    let length = String(answer).length;
    
    let temp = answer.toString().split("").slice(0, length - 2).join("");
    
    if(temp.length) {
        console.log(temp);
    } else {
        console.log(0);
    }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));