#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define all(s) s.begin(),s.end()
#define sz(s) (int)s.size()
using namespace std;
using ll = long long;
using ii = pair<int,int>;
using aa = array<int,3>;
const int N = 1e5+5;
const int blocks = 224;
const ll INF = 1e18;
const int MOD = 1e9+7;
int n, m, u, v, k, U, V, scc = 0, ans = 0, timer = 0;
int a[N], c[N], low[N], num[N], pre[N];
vector <int> adj[N], g[N];
vector <ii> edges;
stack<int> st;
map<ii,int> mp;
set <ii> s;
void dfs(int u,int p){
low[u] = num[u] = ++timer;
bool ok = 0;
st.push(u);
for (int it : adj[u]){
if (it == p && !ok){
ok = 1;
continue;
}
if (!num[it]){
dfs(it,u);
low[u] = min(low[u],low[it]);
} else low[u] = min(low[u],num[it]);
}
if (low[u] == num[u]){
int v = -1;
++scc;
while (v != u){
v = st.top();
st.pop();
c[v] = scc;
}
}
}
void DFS(int u,int p){
num[u] = 1;
for (int it : g[u]){
if (it == p) continue;
DFS(it,u);
pre[u] += pre[it];
}
if (pre[u] < 0) mp[{p,u}] = 1; // đi từ p tới u
else if (pre[u] > 0) mp[{p,u}] = 2; // đi từ u tới p
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
#define name "PHANLUONG"
if (fopen(name".inp","r")){
freopen(name".inp","r",stdin);
freopen(name".out","w",stdout);
}
cin >> n >> m;
for (int i = 1; i <= m; i++){
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
edges.push_back({u,v});
}
for (int i = 1; i <= n; i++){
if (!num[i]) dfs(i,0);
}
for (int i = 1; i <= scc; i++) num[i] = 0;
for (ii it : edges){
tie(u,v) = it;
U = c[u];
V = c[v];
if (U > V) swap(U,V);
if (U != V && s.find({U,V}) == s.end()){
g[U].push_back(V);
g[V].push_back(U);
s.insert({U,V});
}
}
cin >> k;
for (int i = 1; i <= k; i++){
cin >> u >> v;
pre[c[u]]++;
pre[c[v]]--;
}
for (int i = 1; i <= scc; i++){
if (!num[i]) DFS(i,0);
}
for (ii it : edges){
tie(u,v) = it;
U = c[u];
V = c[v];
if (U == V) cout << 'B';
else{
if (mp.count({U,V}) == 0 && mp.count({V,U}) == 0) cout << 'B';
else{
if (mp.count({U,V})){
if (mp[{U,V}] == 1) cout << 'R';
else cout << 'L';
} else{
if (mp[{V,U}] == 1) cout << 'L';
else cout << 'R';
}
}
}
}
return 0;
}
