/*

     stack 容器的应用：    要求字典序升序输出，所以先搜索入栈的

         然后逐个判断是否满足答案，若不满足，回溯继续搜索，输出所有符合的结果

 */

 #include <cstdio>

 #include <iostream>

 #include <algorithm>

 #include <stack>

 #include <cmath>

 #include <cstring>

 #include <vector>

 using namespace std;

 const int MAXN = 1e4 + ;

 const int INF = 0x3f3f3f3f;

 string s1, s2;

 int len;

 stack<char> S;

 vector<char> V;

 void DFS(int push, int pop)

 {

     if (push == len && pop == len)

     {

         for (int i=; i<V.size (); ++i)

             cout << V[i] << " ";

         cout << endl;

     }

     if (push +  <= len)        //入栈

     {

         S.push (s1[push]);

         V.push_back ('i');

         DFS (push+, pop);

         S.pop ();

         V.pop_back ();

     }

     if (pop +  <= push && pop +  <= len && S.top () == s2[pop])        //出栈

     {

         char ch = S.top ();

         S.pop ();

         V.push_back ('o');

         DFS (push, pop+);

         S.push (ch);

         V.pop_back ();

     }

 }

 int main(void)        //ZOJ 1004 Anagrams by Stack

 {

     //freopen ("ZOJ_1004.in", "r", stdin);

     while (cin >> s1 >> s2)

     {

         V.clear ();

         while (!S.empty ())    S.pop ();

         len = s1.length ();

         cout << "[" << endl;

         DFS (, );

         cout << "]" << endl;

     }

     return ;

 }

 /*

 [

 i i i i o o o i o o

 i i i i o o o o i o

 i i o i o i o i o o

 i i o i o i o o i o

 ]

 [

 i o i i i o o i i o o o

 i o i i i o o o i o i o

 i o i o i o i i i o o o

 i o i o i o i o i o i o

 ]

 [

 ]

 [

 i i o i o i o o

 ]

 */