#include <bits/stdc++.h>
#define int long long
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
using namespace std;
int n,m,p;
vector<int> parent;
vector<int> sz;
vector<int> ans;
vector<int> val;
vector<int> visited;
vector<bool> isb;
vector<vector<pair<int,int>>> neigh;
vector<int> tin,low;
int timer=0;
int getParent(int a){
if(parent[a]==a) return parent[a];
return parent[a]=getParent(parent[a]);
}
void unite(int a, int b){
a=getParent(a), b=getParent(b);
if(a==b) return;
if(sz[a]<sz[b]) swap(a,b);
sz[a]+=sz[b];
parent[b]=a;
}
void fb(int x, int p){
if(visited[x]) return;
visited[x]=true;
bool skipParent=false;
tin[x]=low[x]=timer++;
for (auto u : neigh[x])
{
if(u.first==p&&!skipParent){ skipParent=true; continue; }
if(visited[u.first]){
low[x]=min(low[x],low[u.first]);
}else{
fb(u.first,x);
low[x]=min(low[x],low[u.first]);
if(low[u.first]>low[x]) isb[u.second]=true;
}
}
}
int dfs(int x, int p){
if(visited[x]) return 0;
visited[x]=true;
int sm=val[x];
for (auto u : neigh[x])
{
int j=max(u.second,-u.second-1);
int v=dfs(u.first,p);
sm+=v;
if(v==0) continue;
if((v<0&&u.second>=0)||(v>0&&u.second<0)) ans[j]=1;
else ans[j]=2;
}
return sm;
}
signed main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
cin >> n >> m;
ans.resize(m);
val.resize(n);
visited.resize(n);
parent.resize(n);
sz.resize(n);
neigh.resize(n);
isb.resize(m,false);
tin.resize(n,-1);
low.resize(n,-1);
vector<pair<int,int>> ed(m);
for (int i = 0; i < m; i++)
{
int a,b; cin >> a >> b; a--; b--;
ed[i]={a,b};
neigh[a].push_back({b,i});
neigh[b].push_back({a,i});
}
for (int i = 0; i < n; i++) fb(i,i);
for (int i = 0; i < n; i++)
{
parent[i]=i; sz[i]=1;
neigh[i].clear();
visited[i]=0;
}
for (int i = 0; i < m; i++)
{
if(!isb[i]) unite(ed[i].first,ed[i].second);
}
for (int i = 0; i < m; i++)
{
if(isb[i]){
neigh[getParent(ed[i].first)].push_back({getParent(ed[i].second),i});
neigh[getParent(ed[i].second)].push_back({getParent(ed[i].first),-(i+1)});
}
}
int p; cin >> p;
for (int i = 0; i < p; i++)
{
int a,b; cin >> a >> b;
val[getParent(a-1)]++; val[getParent(b-1)]--;
}
for (int i = 0; i < n; i++)
{
if(i!=getParent(i)) continue;
if(!visited[i]) dfs(i,i);
}
for (int i = 0; i < m; i++)
{
if(ans[i]==0) cout << "B";
else if(ans[i]==1) cout << "R";
else cout << "L";
}
return 0;
}
