你们的代码怎么这么长鸭

#include<stdio.h>
int fac(int a){
    for(int i=2;i<=a/2;i++)
        if(a%i==0)
            return 0;
    return 1;
}
int main(){
     int n;
    while(~scanf("%d",&n)){
        int max=2,i=2,another=n-i;
        while(i<=another){
            if(fac(i)&&fac(another))max=i;
            i++;
            another--;
        }
        printf("%d\n%d\n",max,n-max);
    }
}