#include <bits/stdc++.h>
#define REP(i, n) for(int i = 0;i < n;i++)
#define ll long long
using namespace std;
//typedef vector<unsigned int>vec;
//typedef vector<ll>vec;
//typedef vector<vec> mat;
typedef pair<int, int> P;
typedef pair<ll,ll> LP;
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const int INF = 1000000000;
const ll LINF = 1000000000000000000;//1e18
const ll  MOD = 1000000007;
const double PI = acos(-1.0);
const double EPS = 1e-10;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
//template<class T> inline void add(T &a, T b){a = ((a+b) % MOD + MOD) % MOD;};

vector<pair<char, int>> runLengthEncoding(string &s) {
    int n = s.size();

    vector<pair<char, int>> res;
    char pre = s[0];
    int cnt = 1;
    for(int i=1;i<n;i++) {
        if (pre != s[i]) {
            res.push_back({ pre, cnt });
            pre = s[i];
            cnt = 1;
        }
        else cnt++;
    }

    res.push_back({ pre, cnt });
    return res;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    string S;
    cin >> S;
    auto res = runLengthEncoding(S);
    if((int)res.size() == 2 && res[0].first == '1' && res[0].second == 1 && res[1].first == '3') cout << res[1].second << endl;
    else cout << -1 << endl;
}