#include<bits/stdc++.h>
using namespace std;
#define N 100005
#define fi first
#define se second
typedef pair<int, int> ii;
int low[N], id[N], cnt, ncc, val[N], typ[N], n, m, dep[N];
vector<int> adj[N];
set<int> adj2[N];
stack<int> st;
vector<ii> eg;
void dfs(int u, int p){
low[u] = id[u] = ++cnt;
st.push(u);
for (auto x : adj[u]){
if (x == p){
p = -1;
continue;
}
if (id[x]){
low[u] = min(low[u], id[x]);
}
else{
dfs(x, u);
low[u] = min(low[u], low[x]);
}
}
if (id[u] == low[u]){
ncc++;
int s = -1;
while (s != u){
s = st.top();
st.pop();
typ[s] = ncc;
low[s] = id[s] = n + 1;
}
}
}
void getdep(int u, int p){
for (auto x : adj2[u]){
if (x == p) continue;
dep[x] = dep[u] + 1;
getdep(x, u);
val[u] += val[x];
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cin >> n >> m;
for (int i = 1; i <= m; i++){
int u, v;
cin >> u >> v;
eg.push_back({u, v});
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int i = 1; i <= n; i++){
if (!id[i]) dfs(i, 0);
for (auto x : adj[i]){
if (typ[x] != typ[i]){
adj2[typ[x]].insert(typ[i]);
adj2[typ[i]].insert(typ[x]);
}
}
}
int q;
cin >> q;
while (q--){
int a, b;
cin >> a >> b;
val[typ[a]]++;
val[typ[b]]--;
}
for (int i = 1; i <= ncc; i++){
if (!dep[i]){
dep[i] = 1;
getdep(i, 0);
}
}
for (auto x : eg){
int a = typ[x.fi], b = typ[x.se];
if (a == b){
cout << "B";
continue;
}
if (dep[a] > dep[b]){
if (val[a] == 0){
cout << "B";
}
if (val[a] > 0){
cout << "R";
}
if (val[a] < 0){
cout << "L";
}
}
if (dep[a] < dep[b]){
if (val[b] == 0){
cout << "B";
}
if (val[b] > 0){
cout << "L";
}
if (val[b] < 0){
cout << "R";
}
}
}
return 0;
}
