#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;

#define pb push_back

const ld pi = 3.14159265358979323846;
// const int mod = 998244353;
const ll INF = 1e18;

template<typename T>
T chmax(T a, T b) {
    return a > b ? a : b;
}

template<typename T>
T chmin(T a, T b) {
    return a > b ? b : a;
}

const int N = (int)1e6 + 1, M = N * 2;

using lll = __int128;

ostream &operator<<(std::ostream &os, lll n) {
    std::string s;
    while (n) {
        s += '0' + n % 10;
        n /= 10;
    }
    std::reverse(s.begin(), s.end());
    return os << s;
}


ll ceil_div(ll n, ll m) {
    if(n >= 0){
        return (n + m - 1) / m;
    } 
    else{
        return n / m;
    }
}
 
ll floor_div(ll n, ll m) {
    if (n >= 0){
        return n / m;
    } 
    else{
        return (n - m + 1) / m;
    }
}

template<class T>
void chmax(T &a, T b) {
    if(a < b) {
        a = b;
    }
}

lll gcd(lll a, lll b) {
    return b ? gcd(b, a % b) : a;
}

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

    if(s.back() == 'E'){
        cout << "INVALID" << endl;
        return;
    }

    for(int i = 1; i < s.size(); i++){
        if(s[i] == s[i - 1] && s[i] == 'O'){
            cout << "INVALID" << endl;
            return;
        }
    }

    lll qwq = INF;
    for(lll i = 1; i <= 1ll << 60; i *= 2){
        lll owo = i;
        for(int j = s.size() - 1; j >= 0; j--){
            if((owo - 1) % 3 && s[j] == 'O'){
                owo = INF;
                break;
            }
            if(s[j] == 'E'){
                owo *= 2;
            }
            else{
                owo = (owo - 1) / 3;
            }
        }
        if(owo == 0) continue;

        int uwu = 0;
        for(lll j = 1; j < 1ll << 60; j *= 2){
            if(owo == j){
                uwu = 1;
            }
        }

        if(!uwu){
            qwq = chmin(qwq, owo);
        }
    }
    cout << qwq << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int t = 1;
    // cin >> t;

    while(t--){
        solve();
    }

    return 0;
}