from decimal import *



A,B=list(map(Decimal,input().split()))



print((Decimal(str(A*B)).quantize(Decimal('1'), rounding=ROUND_DOWN)))
a,b=input().split()

a=int(a)

b=int(float(b)*1000)

print((int(a*b//1000)))
from decimal import *

A, B = list(map(Decimal, input().split()))
print((Decimal(str(A * B)).quantize(Decimal("1"), rounding=ROUND_DOWN)))

a, b = input().split()
a = int(a)
b = int(float(b) * 1000)
print((int(a * b // 1000)))

-from decimal import * - -A, B = list(map(Decimal, input().split())) -print((Decimal(str(A * B)).quantize(Decimal("1"), rounding=ROUND_DOWN))) +a, b = input().split() +a = int(a) +b = int(float(b) * 1000) +print((int(a * b // 1000)))