#include <bits/stdc++.h>
using namespace std;
#define fi first
#define sc second
#define sz(v) (int)v.size()
const int MAXN = 1*1e5+5, MAX = 16;
vector< pair<int,int> > adj[MAXN], adj2[MAXN];
vector<int> ponte;
int pai[MAXN], s[MAXN], dist[MAXN], low[MAXN], val[MAXN];
int u[MAXN], v[MAXN], ans[MAXN];
int find(int x){
if(pai[x] == x)return x;
return pai[x] = find(pai[x]);
}
void merge(int a, int b){
a = find(a), b = find(b);
if(a == b)return;
if(s[a] < s[b])swap(a,b);
pai[b] = a;
s[a] += s[b];
}
void dfs(int s, int p){
low[s] = dist[s];
int qtd = 0;
for(int i = 0; i < sz(adj[s]); i++){
int viz = adj[s][i].fi, id = adj[s][i].sc;
if(qtd == 0 && viz == p){qtd++; continue;}
if(dist[viz])low[s] = min(low[s],low[viz]);
else{
dist[viz] = dist[s]+1;
dfs(viz,s);
low[s] = min(low[s],low[viz]);
if(low[viz] <= dist[s])merge(s,viz);
else ponte.push_back(id);
}
}
}
void dfs2(int s,int p){
dist[s] = 1;
for(int i = 0; i < sz(adj2[s]); i++){
int viz = adj2[s][i].fi, id = adj2[s][i].sc;
if(viz == p)continue;
dfs2(viz,s);
if(val[viz] < 0){
if(u[id] == s)ans[id] = 1;
else ans[id] = 2;
}
if(val[viz] > 0){
if(u[id] == s)ans[id] = 2;
else ans[id] = 1;
}
val[s] += val[viz];
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n,m; cin>>n>>m;
for(int i = 1; i <= n; i++){
pai[i] = i; s[i] = 1;
}
for(int i = 1; i <= m; i++){
cin>>u[i]>>v[i];
adj[u[i]].emplace_back(v[i],i);
adj[v[i]].emplace_back(u[i],i);
}
for(int i = 1; i <= n; i++)
if(dist[i] == 0){
dist[i] = 1;
dfs(i,0);
}
for(int i = 0; i < sz(ponte); i++){
u[ponte[i]] = find(u[ponte[i]]), v[ponte[i]] = find(v[ponte[i]]);
adj2[u[ponte[i]]].emplace_back(v[ponte[i]],ponte[i]);
adj2[v[ponte[i]]].emplace_back(u[ponte[i]],ponte[i]);
}
int q; cin>>q;
while(q--){
int a,b; cin>>a>>b;
val[find(a)]++; val[find(b)]--;
}
for(int i = 1; i <= n; i++)dist[i] = 0;
for(int i = 1; i <= n; i++)
if(!dist[i])dfs2(i,0);
for(int i = 1; i <= m; i++){
if(ans[i] == 0)cout<<"B";
else if(ans[i] == 1)cout<<"R";
else cout<<"L";
}
cout<<"\n";
}
