View Code of Problem 27

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

}