#include<bits/stdc++.h> using namespace std; const string s=" is substring of "; int main(){ string s1,s2; getline(cin,s1); getline(cin,s2); if(strstr(s2,s1)) cout<<s1<<s3<<s2; else if(strstr(s1,s2)) cout<<s2<<s3<<s1; else cout<<"No substring"; return 0; }