class wb{
    static int toDecimal(String binary,int i) {
        int n = binary.length();
        if (i == n-1)
        return binary.charAt(i) - '0';
        return ((binary.charAt(i) - '0') << (n-i-1)) +
                toDecimal(binary, i+1);
    }
    public static void main(String []args)
    {
        String binary = "1011100010";
        int i=0;
        System.out.println(toDecimal(binary,i));
    }

}