#include<iostream>
#include<string>
#include<cmath>
#include<unordered_map>
using namespace std;

int main() {
    string s;
    unordered_map<char, int> map = 
    {{'0', 0}, {'1', 1}, {'2', 2}, {'3', 3}, {'4', 4}, {'5', 5}, {'6', 6}, {'7', 7}, {'8', 8}, 
    {'9', 9}, {'A', 10}, {'B', 11}, {'C', 12}, {'D', 13}, {'E', 14}, {'F', 15}};
    while (cin >> s) {
        int ans = 0; // 此处一定要初始化
        int len = s.size();
        for (int i = len - 1, j = 0; s[i] != 'x'; --i, j++) {
            ans += map[s[i]] * pow(16, j); // pow的头文件是cmath
        }

        cout << ans << endl;
    }

    return 0;
}