#include <iostream>
#include <string>
#include <vector>

using namespace std;

int f(const string &s, const string &t)
{
    int n = s.length(), m = t.length();

    vector<int> shift(128, m + 1);

    int i, j;

    for (j = 0; j < m; j++)
        shift[t[j]] = m - j;

    for (i = 0; i <= n - m; i += shift[s[i + m]]) {
        j = 0;
        while (j < m && s[i + j] == t[j]) j++;
        if (j == m) return i;
    }

    return -1;
}

int main()
{
    string a, b;
    cin >> a >> b;
    cout << f(a, b) << endl;
    return 0;
}