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 Go (1.14.1) (judge verdict: Accepted)

package main

import (
        "fmt"
        "strconv"
)

func solution(a int, b string) int {
        x := make([]byte, 0, len(b))
        for i := range b {
                if b[i] != '.' {
                        x = append(x, b[i])
                }
        }
        bn, _ := strconv.Atoi(string(x))

        return a * bn / 100
}

func main() {
        var a int
        var b string
        fmt.Scan(&a, &b)
        fmt.Println(solution(a, b))
}