#include<iostream>

 #include<algorithm>

 #include<cstdio>

 #include<cstring>

 #include<string>

 #include<queue>

 using namespace std;

 typedef long long ll;

 const int N=4e5+;

 int vis[N];

 string path[N];

 char map[];

 char index[]="udrl";//因为是逆向所以方向要反一下

 int d[][]={{,},{-,},{,-},{,}};

 int fac[]={,,,,,,,,};

 struct node{

     char num[];

     int pos;

     string path;

 }pre,now;

 //求康托展开值

 int cantor(char s[]){

     int sum=;

     int n=strlen(s);

     for(int i=;i<n;i++){

         int cnt=;

         for(int j=i+;j<n;j++){

             if(s[i]>s[j])

                 cnt++;

         }

         sum+=cnt*fac[n-i-];

     }

     return sum+;

 }

 //从12345678x逆向BFS打表

 void bfs(){

     queue<node>q;

     now.pos=;

     for(int i=;i<;i++)

         now.num[i]=i++'';

     now.num[]='';

     now.num[]='\0';

     q.push(now);

     while(!q.empty()){

         pre=q.front();

         q.pop();

         int pos=pre.pos;

         //转换成二维坐标

         int x=pos/;

         int y=pos%;

         for(int i=;i<;i++){

             int xx=x+d[i][];

             int yy=y+d[i][];

             if(xx<||yy<||xx>||yy>)

                 continue;

             //转换回一维坐标

             int new_pos=xx*+yy;

             now=pre;

             swap(now.num[pos],now.num[new_pos]);

             int tmp=cantor(now.num);

             if(!vis[tmp]){

                 now.pos=new_pos;

                 //index[i]要加在前面，反的嘛

                 now.path=index[i]+now.path;

                 vis[tmp]=;

                 //存储路径

                 path[tmp]=now.path;

                 q.push(now);

             }

         }

     }

 }

 int main(){

     char c;

     bfs();

     while(cin>>c){

         //x转换成0便于康托展开

         if(c=='x')

             map[]='';

         else

             map[]=c;

         for(int i=;i<;i++){

             cin>>map[i];

             if(map[i]=='x')

                 map[i]='';

         }

         int aim=cantor(map);

         if(vis[aim])

             cout<<path[aim]<<endl;

         else

             cout<<"unsolvable"<<endl;

     }

 }