View Code of Problem 27

#include<stdio.h>
#include<string.h>
#include<math.h>
bool isprime(int n)
{
	if(n<= 1)
		return false;
	int sqr = (int)sqrt(1.0 *n);
	for(int i=2;i <= sqr;i++)
	{
		if(n%i ==0)
			return false;
	}
	return true;
}
int main()
{
	long long a,b;
	long long sum = 0;
	while(scanf("%lld %lld",&a,&b) != EOF)
	{
		sum = 0;
		if(a > b)
		{
			int temp = a;
			a = b;
			b = temp;
		}
		for(int i = a+1;i<b;i++)
		{
			if(isprime(i))
				sum = sum + i;
		}
		printf("%lld\n",sum);
	}
	return 0;
}