// Program 19: Recursive Binary to Decimal Conversion

import java.util.*;
class Convert {
    long binum;
    long decinum;
    void input() {
        Scanner sc = new Scanner(System.in);
        binum = sc.nextLong();
    }
    long BintoDeci(long d, long p) {
        if (d == 0) {
            return 0;
        }
        return (d % 10) * p + BintoDeci(d / 10, p * 2);
    }
    void display() {
        long temp = binum;
        if (temp < 0) {
            System.out.println("Invalid binary number");
            return;
        }
        while (temp > 0) {
            if (temp % 10 > 1) {
                System.out.println("Invalid binary number");
                return;
            }
            temp /= 10;
        }
        decinum = BintoDeci(binum, 1);
        System.out.println(binum + " = " + decinum);
    }
    public static void main(String[] args) {
        Convert ob = new Convert();
        ob.input();
        ob.display();
    }
}