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- package aoj.contest1399;
- import java.util.Scanner;
- public class H_Goldbach {
- public static void main(String[] args){
- Scanner cin=new Scanner(System.in);
- int n=cin.nextInt(),sum=0;
- for(int i=n/2;i>=2;i--)
- if(prime(i)&& prime(n-i)) sum++;
- System.out.println(sum);
- cin.close();
- }
-
- private static boolean prime(int n) {
- for(int i=2;i*i<=n;i++)
- if(n%i==0)return false;
- return true;
- }
- }
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