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>
#include<cstdio>
#include<algorithm>
#include<map>
#include<stack>
#include<vector>
#include<string>
#include<cstring>
#include<cmath>
#include<queue>
#include<sstream>
#define ll long long
const int inf = 0x3f3f3f3f;
const int N = 1e3+50;
const ll M = 1e9+7;

using namespace std;



int main()
{
	ios::sync_with_stdio(false);
	ll ans = 0;
	ll a;
	double b;
	cin>>a>>b;
	b*=100;
	ans = a*b/100;
	cout<<ans<<endl;
	return 0;
}