import java.util.Scanner;

public class computer {

    // 将任意进制数转换为十进制数  
    public static int toDecimal(String number, int base) {
        int decimal = 0;
        int power = 0;

        // 从字符串的末尾开始遍历  
        for (int i = number.length() - 1; i >= 0; i--) {
            char digit = number.charAt(i);
            int value;

            // 处理0-9的数字字符  
            if (digit >= '0' && digit <= '9') {
                value = digit - '0';
            }
            // 处理A-F（或a-f）的十六进制字符  
            else if (digit >= 'A' && digit <= 'F') {
                value = digit - 'A' + 10;
            } else if (digit >= 'a' && digit <= 'f') {
                value = digit - 'a' + 10;
            } else {
                throw new IllegalArgumentException("Invalid character in number: " + digit);
            }

            // 根据当前字符的权重（即它在数中的位置）累加其值  
            decimal += value * Math.pow(base, power);
            power++;
        }

        return decimal;
    }




    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // 输入原始进制数和目标进制  
        System.out.print("输入原始数字的基数（2-16）: ");
        int originalBase = scanner.nextInt();

        System.out.print("输入原始数字输入要转换的基数（2-16）: ");
        String originalNumber = scanner.next();

        System.out.print("输入要转换的基数（2-16）: ");
        int targetBase = scanner.nextInt();

        // 转换并输出结果  
        int decimal = toDecimal(originalNumber, originalBase);
        String convertedNumber = fromDecimal(decimal, targetBase);

        System.out.println("转换后的号码是: " + convertedNumber);

        scanner.close();
    }
}