#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define AquA cin.tie(0);ios_base::sync_with_stdio(0);
#define fs first
#define sc second
#define cd complex<double>
#define p_q priority_queue
using namespace std;
vector<vector<pair<int,int> > > e;
vector<int> dfn,low;
vector<int> ans;
vector<int> vis;
vector<int> tt;
int cnt=1,cc=0;
stack<int> sk;
void dfs(int r,int f){
dfn[r]=low[r]=cnt;
cnt++;
sk.push(r);
if(f>=0){
vis[f]=1;
}
for(auto h:e[r]){
if(vis[h.sc]){
continue;
}
if(dfn[h.fs]){
low[r]=min(low[r],dfn[h.fs]);
}
else{
dfs(h.fs,h.sc);
low[r]=min(low[r],low[h.fs]);
if(low[h.fs]>dfn[r]){
cc++;
int k;
do{
k=sk.top();
tt[k]=cc;
sk.pop();
}while(k!=h.fs);
}
}
}
if(f==-1){
cc++;
do{
tt[sk.top()]=cc;
sk.pop();
}while(sk.size());
}
}
vector<vector<pair<int,int> > > ff;
vector<pair<int,int> > eg;
vector<int> kk;
vector<int> vvvvv;
void dfs2(int x,int y,int z){
vvvvv[x]=1;
for(auto h:ff[x]){
if(h.fs!=y){
dfs2(h.fs,x,h.sc);
kk[x]+=kk[h.fs];
}
}
if(kk[x]!=0){
ans[z]=((kk[x]>0)^(x==eg[z].fs))?1:-1;
}
}
int main(){
AquA;
int n,m;
cin >> n >> m;
e.resize(n);
eg.resize(m);
for(int i=0;i<m;i++){
int a,b;
cin >> a >> b;
a--;
b--;
e[a].push_back({b,i});
e[b].push_back({a,i});
eg[i]={a,b};
}
dfn.resize(n);
low.resize(n);
ans.resize(m);
vis.resize(m);
tt.resize(n);
for(int i=0;i<n;i++){
if(!dfn[i]){
dfs(i,-1);
}
}
ff.resize(cc+1);
for(int i=0;i<n;i++){
for(auto h:e[i]){
if(tt[i]!=tt[h.fs]){
ff[tt[i]].push_back({tt[h.fs],h.sc});
}
}
}
for(int i=0;i<m;i++){
eg[i]={tt[eg[i].fs],tt[eg[i].sc]};
}
int p;
cin >> p;
kk.resize(cc+1);
for(int i=0;i<p;i++){
int a,b;
cin >> a >> b;
a--;
b--;
a=tt[a];
b=tt[b];
if(a==b){
continue;
}
kk[a]++;
kk[b]--;
}
/*
for(int i=0;i<=cc;i++){
cout << i << "\n";
for(auto h:ff[i]){
cout << h.fs << " " << h.sc << "\n";
}
cout << "\n";
}
*/
vvvvv.resize(cc+1);
for(int i=1;i<=cc;i++){
if(vvvvv[i]==0){
dfs2(i,0,-1);
}
}
for(int i=0;i<m;i++){
if(ans[i]==0){
cout << "B";
}
else if(ans[i]==1){
cout << "L";
}
else if(ans[i]==-1){
cout << "R";
}
}
return 0;
}
