#warning Check FastIO
#ifdef ONLINE_JUDGE
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#endif
#include <iostream>
#include <algorithm>
#include <climits>
#include <queue>
#include <cmath>
#include <map>
#include <set>
#include <random>
#include <chrono>
#include <iomanip>
#include <vector>
#include <fstream>
using namespace std;
#define vll vector<ll>
#define sll set<ll>
#define vstr vector<string>
#define ll long long
#define ld long double
#define supra main
#define pb push_back
#define add insert
#define rall(x) rbegin(x),rend(x)
#define all(x) (x).begin(),(x).end()
#define I ios_base::sync_with_stdio(false);
#define Hear cin.tie(NULL);
#define Shots cout.tie(NULL);
#define Ratatatata
#define bits_on(a) (__builtin_popcountll(a))
#define mx_pw2(a) (__builtin_ctzll(a))
mt19937 RNG(chrono::steady_clock::now().time_since_epoch().count());
#define SHUFFLE(v) shuffle(all(v), RNG);
const ll inf=LLONG_MAX;
void input(vll& a)
{
for(auto& i:a)
cin>>i;
}
void pyn(bool a)
{
cout<<(a?"YES":"NO")<<endl;
}
ll powmod(ll a,ll b,ll modulo)
{
if(b==0){
return 1;
}
ll temp=powmod(a,b/2,modulo);
if(b%2==0){
return (temp*temp)%modulo;
}
else{
return (a*((temp*temp)%modulo))%modulo;
}
}
bool Prime(ll n){
for (ll i = 2; i*i <= n; i++)
if (n % i == 0)
return false;
return (n>1);
}
void solve()
{
ll n,m;
cin>>n>>m;
vll sas(n),f(m);
input(sas);
input(f);
if(n==1)
{
if(sas[0]<=f[0])
{
cout<<f.back()-sas[0]<<endl;
cout<<'R'<<endl;
}
else if(f.back()<=sas[0])
{
cout<<sas[0]-f[0]<<endl;
cout<<'L'<<endl;
}
else
{
cout<<-1<<endl;
}
}
else if(n<=10)
{
ll s=-1,e=1e9+5;
string tp;
while(s+1<e)
{
ll mid=(s+e)/2;
bool pos=0;
for(ll mask=0;mask<(1<<n);mask++)
{
multiset<ll> cur(all(f));
string ans;
for(int i=0;i<n;i++)
{
int l=sas[i],r=sas[i];
if(mask&(1<<i))
{
ans+='L';
l-=mid;
}
else
{
ans+='R';
r+=mid;
}
auto it=cur.lower_bound(l);
while(it!=end(cur) and (*it)<=r)
{
cur.erase(it);
it=cur.lower_bound(l);
}
}
if(cur.size()==0)
{
pos=1;
tp=ans;
break;
}
}
if(pos)
{
e=mid;
}
else
{
s=mid;
}
}
ll fl=1e9+5;
if(e==fl)
{
cout<<-1<<endl;
}
else
{
cout<<e<<endl;
cout<<tp<<endl;
}
}
else
{
ll s=-1,e=1e9+5;
string tp;
while(s+1<e)
{
ll mid=(s+e)/2;
multiset<ll> cur(all(f));
string ans;
for(int i=0;i<n;i+=3)
{
ans+='L';
ans+='L';
ans+='R';
int l=sas[i],r=sas[i];
l-=mid;
r+=mid;
auto it=cur.lower_bound(l);
while(it!=end(cur) and (*it)<=r)
{
cur.erase(it);
it=cur.lower_bound(l);
}
}
if(cur.size()==0)
{
e=mid;
tp=ans;
}
else
{
s=mid;
}
}
ll fl=1e9+5;
if(e==fl)
{
cout<<-1<<endl;
}
else
{
cout<<e<<endl;
cout<<tp<<endl;
}
}
}
int supra(){
I Hear Shots Ratatatata
ll tqwertyuiop=1;
for(int tp=1;tp<=tqwertyuiop;tp++)
{
// cout<<"Case #"<<tp<<": ";
solve();
}
return 0;
}
/*
Bro use only in a emergency
this is kind of hacking
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
*/
