#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
const ll MOD = 1000000007;
const ll INF = 2147483647;
const ll LINF = 9223372036854775807;
#define REP(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()

int main() {
	string s, t;
    cin >> s >> t;
    int n = s.size(), m = t.size();
    int p = 0;
    int ans = 0;
    REP(i,n){
        if(s[i] == t[p]){
            p++;
            if(p == m){
                ans++;
                if(m != 1)
                    i--;
                p = 0;
            }
        }
    }
    if(m == 1){
        if(ans == 0){
            cout << 0 << endl;
        }
        else{
            cout << -1 << endl;
        }
    }
    else{
        cout << ans << endl;
    }
    return 0;
}