View Code of Problem 30

#include<stdio.h>
#include<math.h>
int main()
{
	int n,num,i,sum;
	while(scanf("%d",&num)!=EOF)
	{	
		sum=0;n=1;
		for(i=0;i<num;i++)
		{	
			sum=sum+n;
			n++;
		}
		printf("%d\n",sum);
	}
	return 0;
}