题解 | #牛牛的等差数列#
牛牛的等差数列
https://www.nowcoder.com/practice/fb9daba67b88437a9e501adf020d425e
import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int a = sc.nextInt();
int b = sc.nextInt();
System.out.print(2*b-a);
}
}
