题解 | #进制转换#

import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        String upperStr = str.toUpperCase();
        int sum = 0;
        int len = upperStr.length();
        for(int i=2; i < len; i++){
            if(upperStr.charAt(i) >= '0' && upperStr.charAt(i) <= '9'){
                sum += (upperStr.charAt(i)- '0') * Math.pow(16, len-i-1);
            }else{
                sum += ((upperStr.charAt(i)- 'A') + 10) * Math.pow(16, len-i-1);
            }
        }
        System.out.println(sum);
        
    }
}