View Code of Problem 30

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