#include<stdio.h>
int main()
{
    int m,i;
    scanf("%d",&m);
    for(i=2;i<m;i++)
    {
        if(m%i==0)
        {
            printf("%d is not a prime number\n",m);
            break;
        }
   
    }
        if(i>=m)
            printf("%d is a prime number\n",m);
   
    return 0;
}    return 0;
} 其中if(i>=m)
            printf("%d is a prime number\n",m);
 为什么放在循环外 而不放内