import java.util.Scanner;
public class perimeterOfSquare
{
public static void main(String args[])
{
Scanner sc=new Scanner(System.in);
System.out.println("Enter a length of square");
double a=sc.nextDouble();
/*Formula of perimeter of square =4*(length of square)*/
double perimeter=4*a;
System.out.println("perimeter of square="+perimeter);
}
}