View Code of Problem 27

#include<stdio.h>
#include<cstdlib>
#include<cmath>
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
int main(){
     int a,b;
     while(scanf("%d%d",&a,&b)==2){
     int i=a+1,sum=0,flag=0;
        for(int i=a+1;i<b;i++){
		for(int j=2;j<i;j++){
         if(i%j==0)  flag=1;
		}
		if(flag==0) sum=sum+i;
		 flag=0;
	 }
	 printf("%d\n",sum);
     }
	  return 0;
}