import Foundation

func readDoubles() -> [Double] {
   return readLine()!.split(separator: " ").map { Double($0)! }
}


func main(){
    let ab = readLine()!.split(separator: " ").map { String($0) }
    
    let a = NSDecimalNumber(string: ab[0])
    let b = NSDecimalNumber(string: ab[1])
    let x = a.multiplying(by: b)
    print(x.intValue)
}

main()

