#include <iostream>
#include <string>
using namespace std;
int main() {
	string c;
	while (cin >> c) {
		int sum = 0, t = 1;
		for (int i = c.size() - 1; i >= 2; i--) {
			int a = c[i] >= 'A' ? c[i] - 'A' + 10 : c[i] - '0';
			sum += a * t;
			t *= 16;
		}
		cout << sum<<endl;
	}
	return 0;
}