View Code of Problem 27

#include <stdio.h>
#include <math.h>
int main(){
  int a,b;
  int i,j;
  long sum;
  int flag;
  while (scanf("%d%d",&a,&b) != EOF){
	  sum=0;
    for(i=a+1;i<b;i++)
		{
			flag=1;
			if(i==1)
			{
				flag=0;
				continue;
			}
	    	for(j=2;j<=sqrt(i);j++)
			{
			if(i%j==0)
			{
			flag=0;
			break;
			}
			}
		
			if(flag)
				sum+=i;
		}
      printf("%ld\n",sum);
    
    }
    
  
  
 
return 0;
}