#include<iostream> #include<stack> using namespace std; void out(string s1,string s2,int low1,int high1,int low2,int high2,stack<char> &s){ if(low1 > high1 || low2 > high2)return; char head = s1.at(low1); int p = low2; while(s2.at(p)!=head)p++; s.push(head); int length1 = p-low2;//1 2 3 4(p) 5 6 7 //4(p) 2 3 1 5 7 6 int length2 = high2-p; out(s1,s2,low1+1,low1+length1,p-length1,p-1,s); out(s1,s2,low1+length1+1,high1,p+1,high2,s); cout<<head; s.pop(); } int main(){ string s1 = ""; string s2 = ""; while(cin>>s1){ if(cin.eof())break; cin>>s2; stack <char>s; out(s1,s2,0,s1.length()-1,0,s2.length()-1,s); cout<<endl; } return 0; }