#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define pb push_back
#define ll long long
#define int long long
const long long inf=1e18;
const int MOD=1e9+7;
const int N=1001;
int n,m;
multiset<int> adj[N];
bool vis[N],ans=0; //pos1=Right po2=Left
int pos1[N],pos2[N];
void func(int node,int goal){
if(node==goal || ans){
ans=1;
return;
}
for(auto i:adj[node]){
if(!vis[i]){
vis[i]=1;
func(i,goal);
}
}
}
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>n>>m;
pair<int,int> a[m];
for(int i=0;i<m;i++){
int x,y; cin>>x>>y;
a[i].first=x; a[i].second=y;
adj[x].insert(y);
adj[y].insert(x);
}
int p; cin>>p;
int fr=p;
while(p--){
int st,en; cin>>st>>en;
for(int i=0;i<m;i++){
int x=a[i].first,y=a[i].second;
adj[y].extract(x);
func(st,en);
if(ans)pos1[i]++;
for(int j=0;j<=n;j++)vis[j]=0;
ans=0;
adj[y].insert(x);
adj[x].extract(y);
func(st,en);
if(ans)pos2[i]++;
for(int j=0;j<=n;j++)vis[j]=0;
ans=0;
adj[x].insert(y);
}
}
for(int i=0;i<m;i++){
if(pos1[i]==fr && pos2[i]==fr)cout<<'B';
else if(pos1[i]==fr)cout<<'R';
else cout<<'L';
}
}
