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;
     while(i>a&&i<b){
         for(int j=2;j<i;j++){
         if(i%j==0){
          flag=1;
		 }
		 }
		 if(flag==0){
		 sum=sum+i;
		 }
		 flag=0;
		 i++;
	 }
	 printf("%d\n",sum);
     
	 
	 }
	  return 0;
}