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 <stdio.h>
int main(void){
	long a;
	// long double b;
	// scanf("%ld", &a);
	// scanf("%Lf", &b);
	// printf("%ld\n", (long)(a*b));
	char b[5];
	scanf("%ld", &a);
	scanf("%s", b);
	long long_b = (b[0]-'0')*100 + (b[2]-'0')*10 + (b[3]-'0');
	printf("%ld\n", long_b);
	printf("%ld\n", a*long_b/100);
	return 0;
}