#include <bits/stdc++.h>
#define rep(i, p, n) for (ll i = p; i < (ll)(n); i++)
#define rep2(i, p, n) for (ll i = p; i >= (ll)(n); i--)
using namespace std;
using ll = long long;
using ld = long double;
const double pi = 3.141592653589793;
const long long inf = 2 * 1e9;
const long long linf = 4 * 1e18;
const ll mod1 = 1000000007;
const ll mod2 = 998244353;
template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return 1;
    }
    return 0;
}

// atcoder
#include <atcoder/all>
using namespace atcoder;
using mint1 = modint1000000007;
using mint2 = modint998244353;

vector<pair<ll, ll>> base = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};

int main()
{

    //////////////////
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    //////////////////

    string S;
    cin >> S;
    if (S.at(0)=='x') {
        ll now = 1;
        rep(i, 0, 32) {
            now *= 2;
        }
        ll temp = 1;
        ll H = S.size();
        rep2(i, H - 1, 1) {
            now -= (temp * (S.at(i) - '0'));
            temp *= 10;
        }
        cout << now;
    }
    else {
        cout << S;
    }
}