import java.util.Scanner;

class sumcalc

{

 int sum;

 sumcalc()

{

sum=0;

}

sumcalc(int limit)

{

sum=calcsum(limit);

}

 int calcsum(int limit)

{

int result=0;

for(int i=0;i<=limit;i++)

{

result+=i;

}

return result;

}

public void disrslt()

{

System.out.println("sum is ="+sum);

}

}

class main

{

public static void main(String[]args)

{

Scanner obj=new Scanner(System.in);

System.out.println("enter limit");

int limit=obj.nextInt();

sumcalc res=new sumcalc(limit);

res.disrslt();

}

}