#include <bits/stdc++.h>
using namespace std;
#define ll int
#define pb push_back
const ll MAXN=1e5+5,LG=19;
ll n,m,i,j,k,timedfs;
int num[MAXN],low[MAXN],id[MAXN],a[MAXN],b[MAXN],mark[MAXN];
int up[MAXN][20],h[MAXN],par[MAXN],bripar[MAXN];
int goup[MAXN],godown[MAXN],addUp[MAXN],addDown[MAXN];
vector<pair<ll,ll>> adj[MAXN],adj1[MAXN];
void dfs(ll u,int pe){
num[u]=low[u]=++timedfs;
for(auto e:adj[u]){
int v=e.first,idEdge=e.second;
if(idEdge==pe) continue;
if(!num[v]){
dfs(v,idEdge);
low[u]=min(low[u],low[v]);
}else low[u]=min(low[u],num[v]);
}
}
void dfs_comp(ll u,ll comp){
stack<int> st; st.push(u); id[u]=comp;
while(!st.empty()){
int x=st.top(); st.pop();
for(auto e:adj[x]){
int v=e.first,idEdge=e.second;
if(id[v]) continue;
bool isBridge=0;
if(num[x]<num[v]&&low[v]>num[x]) isBridge=1;
if(num[v]<num[x]&&low[x]>num[v]) isBridge=1;
if(isBridge) continue;
id[v]=comp; st.push(v);
}
}
}
void dfs1(ll u,ll p){
for(auto e:adj1[u]){
int v=e.first,idEdge=e.second;
if(v==p) continue;
h[v]=h[u]+1;
par[v]=u; bripar[v]=idEdge;
up[v][0]=u;
for(int j=1;j<=LG;j++) up[v][j]=up[ up[v][j-1] ][j-1];
dfs1(v,u);
}
}
int lca(int u,int v){
if(h[u]<h[v]) swap(u,v);
int diff=h[u]-h[v];
for(int j=0;j<=LG;j++) if((diff>>j)&1) u=up[u][j];
if(u==v) return u;
for(int j=LG;j>=0;j--){
if(up[u][j]!=up[v][j]){
u=up[u][j]; v=up[v][j];
}
}
return par[u];
}
void dfs_acc(int u,int p){
for(auto e:adj1[u]){
int v=e.first,idEdge=e.second;
if(v==p) continue;
dfs_acc(v,u);
addUp[u]+=addUp[v];
addDown[u]+=addDown[v];
int f=(h[ id[a[idEdge]] ]<h[ id[b[idEdge]] ]?0:1);
if(addUp[v]>0 && addDown[v]==0) mark[idEdge]=!f;
else if(addDown[v]>0 && addUp[v]==0) mark[idEdge]=f;
else mark[idEdge]=2;
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin>>n>>m;
for(i=1;i<=m;i++){
int u,v;cin>>u>>v; a[i]=u; b[i]=v;
adj[u].pb({v,i}); adj[v].pb({u,i});
}
for(i=1;i<=n;i++) if(!num[i]) dfs(i,0);
int comp=0;
for(i=1;i<=n;i++) if(!id[i]) dfs_comp(i,++comp);
for(i=1;i<=m;i++){
if(id[a[i]]==id[b[i]]) mark[i]=2;
else{
bool isBridge=0;
if(num[a[i]]<num[b[i]]&&low[b[i]]>num[a[i]]) isBridge=1;
if(num[b[i]]<num[a[i]]&&low[a[i]]>num[b[i]]) isBridge=1;
if(isBridge){
adj1[id[a[i]]].pb({id[b[i]],i});
adj1[id[b[i]]].pb({id[a[i]],i});
}else mark[i]=2;
}
}
for(i=1;i<=comp;i++) if(!h[i]){h[i]=0; up[i][0]=i; dfs1(i,0);}
cin>>k;
for(i=1;i<=k;i++){
int u,v;cin>>u>>v; u=id[u]; v=id[v];
if(u==v) continue;
int w=lca(u,v);
addUp[u]++; addUp[w]--;
addDown[v]++; addDown[w]--;
}
for(i=1;i<=comp;i++) if(par[i]==0) dfs_acc(i,0);
for(i=1;i<=m;i++){
if(mark[i]==0) cout<<'R';
else if(mark[i]==1) cout<<'L';
else cout<<'B';
}
cout<<"\n";
}
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