from math import floor



a, b = input().split()

a = int(a)

b = int(float(b)*100+0.0001)



print((a*b//100))
a, b = input().split()

a = int(a)

b = round(float(b)*100)



print((a*b//100))
from math import floor

a, b = input().split()
a = int(a)
b = int(float(b) * 100 + 0.0001)
print((a * b // 100))

a, b = input().split()
a = int(a)
b = round(float(b) * 100)
print((a * b // 100))

-from math import floor - -b = int(float(b) * 100 + 0.0001) +b = round(float(b) * 100)