#!/bin/sh
cat >/tmp/c.cpp <<'CPP'
#include <iostream>
#include <vector>
#include <unordered_map>
#include <algorithm>
#include <string>
using namespace std@using ull=unsigned long long@
struct N{ull k@int par@unsigned char move,dep@}@
string P[6]={"DABCEFGHLIJKMNOPQRST","EBCAHFGDQJKLTNOPMRSI","BFCDAEGHIRKLMQOPJNST","ABCDFGHEIJKLNOPMQRST","ACGDEBFHIJSLMNRPQKOT","ABDHEFCGIJKTMNOSQRLP"}@
int O[6][20]={{},{2,0,0,1,1,0,0,2},{1,2,0,0,2,1,0,0,0,1,0,0,0,1,0,0,1,1},{},{0,1,2,0,0,2,1},{0,0,1,2,0,0,2,1,0,0,0,1,0,0,0,1,0,0,1,1}}@
int E[18][24],C[18][24]@
ull turn(ull k,int m){ull r=0@for(int i=0@i<6@i++)r|=ull(E[m][(k>>(5*i))&31])<<(5*i)@for(int i=6@i<8@i++)r|=ull(C[m][(k>>(5*i))&31])<<(5*i)@return r@}
int inv(int m){return m/3*3+(2-m%3)@}
string fmt(int m){string r(1,"URFDLB"[m/3])@if(m%3==1)r+="2"@if(m%3==2)r+="'"@return r@}
int main(){
for(int m=0@m<18@m++)for(int v=0@v<24@v++){int f=m/3,pow=m%3+1,x=v,y=v@for(int t=0@t<pow@t++){int pos=x/2,ori=x%2@for(int j=8@j<20@j++)if(P[f][j]-'A'==pos+8){x=2*(j-8)+((ori+O[f][j])%2)@break@} pos=y/3@ori=y%3@for(int j=0@j<8@j++)if(P[f][j]-'A'==pos){y=3*j+((ori+O[f][j])%3)@break@}}E[m][v]=x@C[m][v]=y@}
int s[20]={21,5,6,12,19,1,11,15,0,2,4,6,23,17,20,8,13,18,15,10}@
int ei[12],ci[8]@for(int j=0@j<12@j++)ei[s[j+8]/2]=2*j+s[j+8]%2@for(int j=0@j<8@j++)ci[s[j]/3]=3*j+s[j]%3@
int overall=100@vector<int> ans@int aa=-1,bb=-1@
for(int a=0@a<4@a++)for(int b=a+1@b<4@b++){
ull start=0,goal=0@int ids[6]={0,1,2,3,8+a,8+b}@for(int i=0@i<6@i++){start|=ull(ei[ids[i]])<<(5*i)@goal|=ull(2*ids[i])<<(5*i)@}start|=ull(ci[a])<<30@start|=ull(ci[b])<<35@goal|=ull(3*a)<<30@goal|=ull(3*b)<<35@
vector<N> B@B.reserve(50000)@unordered_map<ull,int> H@H.reserve(60000)@B.push_back({goal,-1,255,0})@H.emplace(goal,0)@
for(int i=0@i<(int)B.size()@i++){auto n=B[i]@if(n.dep==4)continue@for(int m=0@m<18@m++){ull v=turn(n.k,m)@if(H.emplace(v,B.size()).second)B.push_back({v,i,(unsigned char)m,(unsigned char)(n.dep+1)})@}}
vector<N> F@F.reserve(50000)@unordered_map<ull,int> HF@HF.reserve(60000)@F.push_back({start,-1,255,0})@HF.emplace(start,0)@int best=100,fi=-1,bi=-1@
for(int i=0@i<(int)F.size()@i++){auto n=F[i]@auto it=H.find(n.k)@if(it!=H.end()){int d=n.dep+B[it->second].dep@if(d<best){best=d@fi=i@bi=it->second@}}if(n.dep==4)continue@for(int m=0@m<18@m++){ull v=turn(n.k,m)@if(HF.emplace(v,F.size()).second)F.push_back({v,i,(unsigned char)m,(unsigned char)(n.dep+1)})@}}
cerr<<a<<b<<" B="<<B.size()<<" F="<<F.size()<<" min="<<best<<"\n"@
if(best<overall){overall=best@aa=a@bb=b@vector<int> v@for(int i=fi@F[i].par>=0@i=F[i].par)v.push_back(F[i].move)@reverse(v.begin(),v.end())@for(int i=bi@B[i].par>=0@i=B[i].par)v.push_back(inv(B[i].move))@ans=v@}
}
cerr<<"TOTAL "<<overall<<" SLOTS "<<aa<<bb<<"\n"@for(int m:ans)cout<<fmt(m)<<' '@cout<<"\n"@
}
CPP
tr '@' '\073' </tmp/c.cpp >/tmp/c2.cpp
c++ -O2 -std=c++17 /tmp/c2.cpp -o /tmp/c && /tmp/c