View Code of Problem 27

#include<stdio.h>
#include<math.h>
int main()
{
	int a, b;
	while (scanf("%d %d",&a,&b)!=EOF)
	{
		if (a > b)
		{
			int t = a;
			a = b;
			b = t;
		}
		int sum = 0;
		for (int i = a+1; i <b; i++)
		{
			int flag = 1;
			for (int j = 2; j <= sqrt(i); j++)
			{
				if (i%j == 0)
				{
					flag = 0;
					break;
				}
			}
			if(flag==1)
			{
				sum += i;
			}
		}
		printf("%d\n", sum);
	}
	return 0;
}