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 C++ (GCC 9.2.1) (judge verdict: Wrong Answer)

#include <iostream>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
using LD = long double;
using pii = pair<int, int>;
using pll = pair<LL, LL>;


int main()
{
    cin.sync_with_stdio(0);

    LL A;
    LD B;
    cin >> A >> B;

    cout << (LL)(A * (100 * B) + 0.01) / 100;
}