#include <iostream>
#include <cmath>

using namespace std;

int main() {
    long long binaryNumber;

    cin >> binaryNumber;

    long long decimalNumber = 0;
    int power = 0;

    while (binaryNumber != 0) {
        int digit = binaryNumber % 10;
        decimalNumber += digit * pow(2, power);
        binaryNumber /= 10;
        power++;
    }

    cout << "Decimal: " << decimalNumber << endl;

    return 0;
}