View Code of Problem 27

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