#include <iostream>
#include <algorithm>
#include <string>

using namespace std;

int main()
{
    string normal, rotated;
    int rotations=0;
    cin >> normal >> rotated;
    while(normal != rotated && rotations <10000)
    {
        std::rotate(normal.rbegin(), normal.rbegin() + 1, normal.rend());
        rotations++;
    }
    if(rotations==10000) cout << -1;
    else cout << rotations;
    return 0;
}