#include <bits/stdc++.h> using namespace std; using ll = long long; using ld = long double; #define fi first #define se second #define vi vector<int> #define vll vector<long long> #define pii pair<int, int> #define pll pair<long long, long long> #define pb push_back #define mp make_pair #define eb emplace_back #define all(x) (x).begin(), (x).end() #define sz(x) (int)(x).size() mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count()); inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);} inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);} #ifdef DEBUG auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";} auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";} #define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X) #else #define debug(...){} #endif struct custom_hash { static uint64_t splitmix64(uint64_t x) { x += 0x9e3779b97f4a7c15; x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9; x = (x ^ (x >> 27)) * 0x94d049bb133111eb; return x ^ (x >> 31); } size_t operator()(uint64_t x) const { static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count(); return splitmix64(x + FIXED_RANDOM); } }; struct pair_hash{ size_t operator()(const pair<int,int>&x)const{ return hash<long long>()(((long long)x.first)^(((long long)x.second)<<32)); } }; int n, m; vi a, b; string ans = ""; bool check(int K){ //b - kwiatki int wsk1 = 0; int wsk2 = 0; int range = -1; ans = ""; while(true){ while(wsk2 < sz(b) && b[wsk2] <= range){ wsk2++; } while(wsk1 < sz(a) && wsk2 < sz(b) && a[wsk1] <= b[wsk2]){ range = max(range, a[wsk1] + K); ans.pb('R'); wsk1++; while(wsk2 < sz(b) && b[wsk2] <= range){ wsk2++; } } if(wsk2 == sz(b)){ while(sz(ans) != sz(a)){ ans.pb('L'); } return true; } if(wsk1 == sz(a)){ return range >= b.back(); } if(a[wsk1] - K > b[wsk2]){ return false; } int pocz = wsk1; while(wsk1 + 1 < sz(a) && a[wsk1 + 1] - K <= b[wsk2]){ wsk1++; } if(pocz == wsk1){ ans.pb('L'); range = max(range, a[wsk1]); wsk1++; }else if(wsk1 == pocz + 1){ int f = 0; while(wsk2 < sz(b) && b[wsk2] <= a[pocz]){ wsk2++; } if(wsk2 < sz(b) && b[wsk2] < a[wsk1]){ f = 1; } if(f){ ans.pb('R'); ans.pb('L'); range = max(range, max(a[wsk1], a[pocz] + K)); }else{ ans.pb('L'); ans.pb('R'); range = max(range, a[wsk1] + K); } wsk1++; }else{ string add = ""; for(int j = pocz; j <= wsk1; j++){ add.pb('R'); } add[sz(add) - 2] = 'L'; ans += add; range = max(range, a[wsk1] + K); wsk1++; } } } int main(){ ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL); cin >> n >> m; a.resize(n); for(int i = 0; i < n; i++){ cin >> a[i]; } b.resize(m); for(int i = 0; i < m; i++){ cin >> b[i]; } int l = 0; int p = (int)1e9; int mid; while(l < p){ mid = (l + p) / 2; if(check(mid)){ p = mid; }else{ l = mid + 1; } } if(!check(l)){ cout << "-1\n"; return 0; } cout << l << '\n'; cout << ans << '\n'; return 0; }