java-MT36 连线游戏
import java.util.Scanner;
public class Main {
public static void main(String[] args){
Scanner in = new Scanner(System.in);
while(in.hasNext()){
solution(in);
}
}
/**
* 画图法
*
* 画图举例子找规律
*
* n=4: N1 N2 N3 N4
* 先画一圈 n个: N1N2 N2N3 N3N4 N4N1
* 再画中间 (n-3)个: N1N3 或 N2N4
*/
private static void solution(Scanner in){
int n = in.nextInt();
System.out.println(n+(n-3));
}
}