题解 | #进制转换#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        int sum = 0;
        for (int i = 0; i < s.length() - 2; i++) {
            char c = s.charAt(i + 2);
            int temp = 0;
            if (c >= '0' && c <= '9')
                temp = c - '0';
            else if (c >= 'A' && c <= 'F')
                temp = c - 'A' + 10;
            else if (c >= 'a' && c <= 'f')
                temp = c - 'a' + 10;
            sum += temp * Math.pow(16, s.length() - i - 3);
        }
        System.out.println(sum);
    }
}