HexdToDecimal

import java.io.*;

class GFG {

	static int hexadecimalToDecimal(String hexVal)
	{
		int len = hexVal.length();

		int base = 1;

		int dec_val = 0;

		for (int i = len - 1; i >= 0; i--) {

			if (hexVal.charAt(i) >= '0'
				&& hexVal.charAt(i) <= '9') {
				dec_val += (hexVal.charAt(i) - 48) * base;

				base = base * 16;
			}

			else if (hexVal.charAt(i) >= 'A'
					&& hexVal.charAt(i) <= 'F') {
				dec_val += (hexVal.charAt(i) - 55) * base;

				base = base * 16;
			}
		}

		return dec_val;
	}

	public static void main(String[] args)
	{
		String hexNum = "1A";

		System.out.println(hexadecimalToDecimal(hexNum));
	}
}