#include <bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;

template <class T> using v = vector<T>;
using ll = long long;
using dd = long double;
using int2 = pair<int, int>;
using ll2 = pair<ll, ll>;
using dd2 = pair<dd, dd>;

#define f first
#define s second
#define all(x) begin(x), end(x)
istream &__cin = cin;
#ifdef DEV_MODE
#include "debug.h"
__cinwrapper __cin_wrapper;
#define cin __cin_wrapper
#else
#define dbg(...)
#define dbg2d(...)
#endif

template <class T1, class T2>
istream &operator>>(istream &in, pair<T1, T2> &p) {
  in >> p.first >> p.second;
  return in;
}
template <class T> istream &operator>>(istream &in, v<T> &v) {
  for (auto &x : v)
    in >> x;
  return in;
}
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

/*
 _______________________________________
( If you don't fail at least 90% of the )
( time, you're not aiming high enough.  )
(                                       )
( - Alan Kay                            )
 ---------------------------------------
        o   ^__^
         o  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||
*/

const bool INTERACTIVE = false;
const bool MULTITEST = false;
/******************************************************************************/

#pragma region templates
using i128 = __int128;
using u128 = __uint128_t;
ostream &operator<<(ostream &out, i128 x) {
  if (x == 0)
    return out << "0";
  string y = "";
  bool neg = x < 0;
  if (neg)
    x = -x;
  while (x) {
    y.push_back((char)(x % 10) + '0');
    x /= 10;
  }
  if (neg) {
    y.push_back('-');
  }
  reverse(all(y));
  return out << y;
}
ostream &operator<<(ostream &out, u128 x) {
  if (x == 0)
    return out << "0";
  string y = "";
  while (x) {
    y.push_back((char)(x % 10) + '0');
    x /= 10;
  }
  reverse(all(y));
  return out << y;
}
#pragma endregion templates

void solve() {
  string s;
  cin >> s;

  for (int i = 1; i < (int)s.size(); i++) {
    if (s[i - 1] == 'O' && s[i] == 'O') {
      cout << "INVALID\n";
      return;
    }
  }
  if (s.back() != 'O') {
    cout << "INVALID\n";
    return;
  }
  for (auto x : s) {
    if (x != 'O' && x != 'E') {
      cout << "INVALID\n";
      return;
    }
  }

  reverse(all(s));
  u128 ans = ~0;
  for (u128 e = 4; e; e <<= 1) {
    u128 cur = e;
    bool ok = 1;
    for (auto x : s) {
      if (x == 'O') {
        if (cur % 6 != 4) {
          ok = 0;
          break;
        }
        cur = (cur - 1) / 3;
      } else {
        if (cur >= (u128)1 << 127) {
          ok = 0;
          break;
        }
        cur *= 2;
      }
      int z = 0;
      for (int i = 0; i < 128; i++) {
        if (cur & ((u128)1 << i))
          z++;
      }
      if (z <= 1) {
        ok = 0;
        break;
      }
    }
    if (ok)
      ans = min(ans, cur);
  }
  cout << ans;
}

int main() {
#ifdef DEV_MODE
  debug_start(INTERACTIVE, "c.txt");
#else
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
#endif
  int t;
  if (MULTITEST)
    cin >> t;
  else
    t = 1;
  while (t--)
    solve();

#ifdef DEV_MODE
  debug_exit(INTERACTIVE);
#endif
}
#ifdef DEV_MODE
#include "debug.cpp"
#endif