80分求助，错在#1 #4上!!!

#include<bits/stdc++.h>
using namespace std;
string a,b;
int main(){
	cin>>a>>b;
	 if(a==b){
	 	cout<<b<<" is substring of "<<a<<endl;
	 }
    else if(b==a){
    	cout<<a<<" is substring of "<<b<<endl;
	}
    else{
    	cout<<"No substring"<<endl;
	}
}