题解

#include<bits/stdc++.h>
using namespace std;
void dfs(string x,string y){
	if(x.size()==0)return;
	int soot=x.find(y[y.size()-1]);
	cout<<x[soot];
	dfs(x.substr(0,soot),y.substr(0,soot));
	dfs(x.substr(soot+1,x.size()-soot),y.substr(soot,y.size()-soot-1));
}
int main(){
	string a,b;
	cin>>a>>b;
	dfs(a,b); 
	return 0;
}