#include<iostream>
using namespace std;
int main() {
	string num16;
	while (cin >> num16) {
		unsigned long long sum = 0;
		for (int i = 2; i < num16.size(); i++) {
			sum *= 16;
			if (num16[i] >= '0' && num16[i] <= '9') sum += num16[i] - 48;
			else if (num16[i] >= 'A' && num16[i] <= 'F') sum += num16[i] - 55;
		}
		cout << sum << endl;
		num16.clear();
	}
}