# include <stdio.h>

int sum(int low,int upper)
{
	int s=0.0;
	int i;
	for(i=low;i<=upper;i++)
	{
		s=s+i;
	}
	return s;
}

int main()
{
	
	int a,b,s;
	printf("Dose to kato orio ?");
	scanf("%d",&a);
	printf("Dose to pano orio ?");
	scanf("%d",&b);
	s=sum(a,b);
	printf("Apotelesma = %d\n",s);
	return 0;
}