View Code of Problem 103

#include "iostream"
#include "stdio.h"
#include "math.h"
#include "algorithm"
using namespace std;

bool isSu(int n){
    for(int i=2;i<=sqrt(n);i++){
        if(n%i==0){
            return false;
        }
    }
    return true;
}

int main(){
    int a,b;
    while (scanf("%d %d",&a,&b)!=EOF){
        int ans=0;
        while (a<b){
            if(isSu(a)){
                ans++;
            }
            if(isSu(b)){
                ans++;
            }
            a++;
            b--;
        }
        if(a==b&&isSu(a)){
            ans++;
        }
        printf("%d\n",ans);
    }
}

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