#include<bits/stdc++.h>
using namespace std;
int main()
{
	string s1,s2;
	cin>>s1>>s2;
	if(s1.find(s2)!=-1)
	{
		cout<<s1.find(s2);
	}
	else
	{
		cout<<-1;
	}
	return 0;
}

#include<bits/stdc++.h> using namespace std; int main(){ string s1,s2; cin>>s1>>s2; if(s1.find(s2)!=-1) { cout<<s1.find(s2); } else { cout<<-1; } return 0; }

#include<bits/stdc++.h> using namespace std; int main(){ string s1,s2; cin>>s1>>s2; if(s1.find(s2)!=-1) { cout<<s1.find(s2); } else { cout<<-1; } return 0; }