#include<bits/stdc++.h>
using namespace std;
#define int long long
#pragma GCC optimize("O3,unroll-loops")
const int maxn=1e5;
int n,m;
vector<pair<int,int> >adj[maxn+2];
int dsu[maxn+2],val[maxn+2],vis[maxn+2];
int bridge[maxn+2],disc[maxn+2],low[maxn+2],ans[maxn+2];
pair<int,int>road[maxn+2];
int fin(int a){
if(dsu[a]==a)return a;
return dsu[a]=fin(dsu[a]);
}
void merg(int a,int b){
a=fin(a); b=fin(b);
if(a==b)return ;
dsu[a]=b;
}
void dfs(int cur,int par){
low[cur]=disc[cur]=disc[par]+1;
int cnt=0;
for(auto x : adj[cur]){
if(cnt==0 && x.first==par){
cnt++; continue;
}
if(disc[x.first]){
low[cur]=min(low[cur],low[x.first]);
}
else{
dfs(x.first,cur);
if(low[x.first]>disc[cur]){
bridge[x.second]=1;
}
low[cur]=min(low[cur],low[x.first]);
}
}
}
void dfs2(int cur,int par){
vis[cur]=true;
for(auto x : adj[cur]){
if(x.first==par)continue;
dfs2(x.first,cur);
val[cur]+=val[x.first];
if(val[x.first]>0){
if(road[x.second].first==cur){
ans[x.second]=2;
}
else{
ans[x.second]=1;
}
}
else if(val[x.first]<0){
if(road[x.second].first==cur){
ans[x.second]=1;
}
else{
ans[x.second]=2;
}
}
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>n>>m;
for(int q=1;q<=n;q++){
dsu[q]=q;
}
for(int q=1;q<=m;q++){
int u,v;
cin>>u>>v;
adj[u].push_back({v,q});
adj[v].push_back({u,q});
road[q]={u,v};
}
for(int q=1;q<=n;q++){
if(disc[q])continue;
dfs(q,0);
}
for(int q=1;q<=m;q++){
if(!bridge[q])merg(road[q].first,road[q].second);
}
for(int q=1;q<=n;q++)adj[q].clear();
for(int q=1;q<=m;q++){
if(bridge[q]){
adj[fin(road[q].first)].push_back({fin(road[q].second),q});
adj[fin(road[q].second)].push_back({fin(road[q].first),q});
}
}
int qu;
cin>>qu;
while(qu--){
int u,v;
cin>>u>>v;
val[fin(u)]++; val[fin(v)]--;
}
for(int q=1;q<=n;q++){
if(fin(q)!=q )continue;
dfs2(q,0);
}
for(int q=1;q<=m;q++){
if(ans[q]==0){
cout<<'B';
}
else if(ans[q]==1){
cout<<'R';
}
else{
cout<<'L';
}
}
cout<<endl;
}
