AC

# include <bits/stdc++.h>
using namespace std;
const string egg="�";
void f(string a,string b){
    cout<<a<<" is substring of "<<b;
}
int main(){
	string m,c;
    cin>>m>>c;
    if (m.find(c) != -1){
        f(c,m);
    }else if (c.find(m) != -1){
        f(m,c);
    }else{
        cout<<"No substring";
    }
	return 0;
}