import java.io.*;
import java.text.*;
//
//Parameter passing
//
//This program also demonstrations the use of a function that returns a value
//

public class program7
{

	public static int Summation(int n) throws IOException
	{
		int sum=0;

		for(int count=1;count<=n;count++)
			sum=sum+count;
	
		return sum;
	}

	public static void main(String[] args) throws IOException
	{
		boolean done=false;
		String choice;

		int number=0;
		int answer=0;

		System.out.println("This program calculates a "+
		" summation.\n");
		BufferedReader in =new BufferedReader
		(new InputStreamReader(System.in));

		do
		{
			System.out.println("Enter the value to calculate: ");

			number=Integer.parseInt(in.readLine());
			answer=Summation(number);
		
			System.out.println("The summation of "+number+" is: "+answer+
			".\n");
			System.out.println("Do you want to do another: "
			+ "(y/n)?");
			choice=in.readLine();
			if (choice.equals("n"))
				done=true;
		}
		while(!done);//or: done==false

		System.out.println("\nProgram Over, Bye!!!\n");
	}

}