#include<stdio.h>
#include<math.h>
int is(int x) //判断一个数是否为素数，是素数返回1，否则返回0
{
int n , i;
n = sqrt(x);
for(i = 2; i <=n; i++)
{
if(x%i == 0)
return 0;
}
return 1;
}
int main()
{
int num1,num2 , i;
int s;
for(i = 1000; i < 2000; i+= 2)
{
num1 = 2;
s = i/2;
while(num1 <= s)
{
if(is(num1)) //如果第一个数是素数
{
num2 = i-num1;
if( is(num2) )
break;
}
num1++;
}
if(num1 == s + 1)
{
printf("%d is mot Ok!\n",i);
break;
}
}
if(i == 2000)
printf("all numbers are Ok!\n");
return 1;
}
