View Code of Problem 27

#include<iostream>
#include<cmath>

using namespace std;
int main(){
	int a, b;
	while (cin >> a){
		cin >> b;
		if (a > b) {
			int temp = a;
			a = b;
			b = temp;
		}
		int sum=0;
		for (int i = a+1; i <b; i++)
		{
			//1不是质数
			if ( i == 2 || i == 3) {
				sum += i;
				continue;
			}
			for (int j = 2; j <=sqrt(i); j++)
			{
				
				if (i % j == 0) {
					break;
				}
				if (j == (int)sqrt(i)) {
					sum += i;
				}
			}
		}
		cout << sum << endl;
		
	}
}