import java.util.Arrays;
import java.security.MessageDigest;

/**
  * Converts a 64 characters long hex private key
  * into a base58 WIF private key (starts with a '5')
  */
public class HexToWIF
{
	public static byte[] getExtendedKey(String s)
	{
   		int len = (s.length() / 2) + 1;
		byte[] data = new byte[len];
		data[0] = (byte) 0x80;
		for (int i = 0; i < s.length(); i += 2)
		{
      			data[(i + 2) / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
                              		   + Character.digit(s.charAt(i+1), 16));
    		}
    		return data;
	}

	public static void main(String[] args)
	{
		if (args.length != 1)
		{
			System.out.println("Wrong number of arguments");
			return;
		}

		byte[] extendedKey = getExtendedKey(args[0]);

		try {
			var sha = MessageDigest.getInstance("SHA-256");
			byte[] hash = sha.digest(extendedKey);
			hash = sha.digest(hash);
			extendedKey = Arrays.copyOf(extendedKey, 37);
			System.arraycopy(hash, 0, extendedKey, 33, 4);
			String privateKey = Base58.encode(extendedKey);
			System.out.println(privateKey);
		}
		catch (Exception e) {
		}
	}
}