自己看

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
string s,t;
int main(){
	//freopen(".in","r",stdin);
	//freopen(".out","w",stdout);
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	std::cout.tie(nullptr);
	cin>>s>>t;
    if(t.find(s)!=string::npos){
        cout<<s<<" is substring of "<<t<<endl;
    }else{
        if(s.find(t)!=string::npos){
            cout<<t<<" is substring of "<<s<<endl;
        }else{
            cout<<"No substring"<<endl;
        }
    }
	//fclose(stdin);
	//fclose(stdout);
	return 0;
}
//coder::by::M91