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 Python (3.8.2) (judge verdict: Runtime Error)

import math

A, B = list(input().split())
A = int(A)
B = '{:.2f}'.format(B).replace('.', '')
B = int(B)

# A *= 100
# B = int(B * 100)


AB = A * B / 100
floored = int(math.floor(AB))
print(floored)

# AB = A * B
# AB = str(AB)
# AB = AB[0:-2]
# AB = 0 if AB == '' else AB
# print(AB)