C语言编程 1.11 寻找素数对

#include<stdio.h>
#include<math.h>
int sushu(long long n)
        {
            long long sqrt_n=sqrt(n);
            for(long long i=2;i<=sqrt_n;i++)
                {
                    if(n%i==0)
                        {
                            return 0;
                        }                       
                }
        return 1;       
        }
int main()
{
    long long M,i;
    while(scanf("%lld",&M)!= EOF)
        {   long long K;
            K=M;
            for(long long i=K/2;i<=K;i++)
                {
                    if(sushu(i)&&sushu(K-i))
                        {
                            printf("%lld %lld\n",K-i,i);
                            break;
                        }
                } 
        }
        return 0;
}