//A tree without skin will surely die.
//A man without face is invincible.
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(S) ((int)S.size())
#define FOR(i, st_, n) for(int i = st_; i < n; ++i)
#define RFOR(i, n, end_) for(int i = (n)-1; i >= end_; --i)
#define x first
#define y second
#define pb push_back
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef unsigned long long ull;
typedef long double LD;
typedef pair<ull, ull> pull;
using namespace __gnu_pbds;
typedef tree<ll, null_type, less<>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
using namespace std;
#ifdef ONPC
mt19937 rnd(228);
#else
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
#endif


ll next(ll x)
{
	if(x%2==0)return x/2;
	return x*3+1;
}

__int128 prev(__int128 x)
{
	if((x-1) % 3 == 0)
		return (x-1)/3;
	else return x*2;
}

int solve()
{
	string s;
	if(!(cin>>s))return 1;
	int n=sz(s);
	bool ok=true;
	if(s[n-1] == 'E')ok=false;
	FOR(i,0,n) if(!(s[i]=='E' || s[i] == 'O'))ok=false;
	FOR(i,0,n-1)
	{
		if(s[i]=='O' && s[i+1]=='O')ok=false;
	}
	if(ok)
	{
		for(__int128 i = 1; i <= 120; ++i)
		{
			string t;
			__int128 num=((__int128)1 << i);
			while(sz(t) < n)
			{
				num=prev(num);
				if(num % 2==0)
					t += 'E';
				else
					t += 'O';
			}
			reverse(all(t));
			if(t==s)
			{
				cout<<(ll)num<<'\n';
				return 0;
			}
		}
		cout<<"INVALID\n";
	}
	else
	{
		cout<<"INVALID\n";
	}
    return 0;
}

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    int TET = 1e9;
    //cin >> TET;
    for (int i = 1; i <= TET; i++)
    {
        if (solve())
        {
            break;
        }
#ifdef ONPC
        cout << "__________________________" << endl;
#endif
    }
#ifdef ONPC
    cerr << endl << "finished in " << clock() * 1.0 / CLOCKS_PER_SEC << " sec" << endl;
#endif
}