#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    string s, t;
    cin >> s >> t;
    s += '*';
    ll ns = len(s), nt = len(t);
    if (nt == 1) {
        bool f = false;
        rep(i, ns) {
            if (s[i] == t[0]) {
                f = false;
                break;
            }
        }
        if (f) cout << -1 << endl;
        else cout << 0 << endl;
        return 0;
    }
    string tmp = "";
    ll ans = 0;
    rep(i, ns) {
        if (s[i] == t[len(tmp)]) {
            tmp += s[i];
            if (tmp == t) {
                ans++;
                if (s[i] == t[0]) tmp = s[i];
                else tmp = "";
            }
        }
        else {
            tmp = "";
        }
    }
    cout << ans << endl;
    return 0;
}