#include<stdio.h>
bool isprime(int k)
{
    int i,j;
    printf("输入一个数\n");
        scanf("%d",&k);
        for(i=2;i<k;i++)
        {
            for(j=2;j<i;j++)
            {
        if(i%j==0)
            return 1;
        else
            return 0 ;
            }
   
        void main()
        {
            int m;
         if(isprime(m))
             printf("%d",i);
        }
             else
             printf("no\n");
        }
}