#include <bits/stdc++.h>
using namespace std;
#define yes cout<<"YES"<<'\n'
#define no cout<<"NO"<<'\n'
#define si size()
#define fi first
#define se second
#define ll int
#define sr sort
#define pb push_back
const ll MAXN=1e5+5,MOD=1e6,LG=19;
ll n,m,j,k,p,i,f,dem,ans,t,l,r=1,timedfs,id[MAXN],num[MAXN];
ll low[MAXN],mark[MAXN],a[MAXN],b[MAXN],up[MAXN][20];
ll goup[MAXN],godown[MAXN],cntup[MAXN],cntdown[MAXN];
ll h[MAXN],par[MAXN],bripar[MAXN];
stack<ll> scc;
vector<pair<ll,ll>> adj[MAXN],adj1[MAXN];
vector<ll> child[MAXN];
map<pair<ll,ll>,ll> ma;
ll comp;
void dfs(ll st,ll preEdge){
num[st]=low[st]=++timedfs;
scc.push(st);
for(auto x:adj[st]){
ll v=x.fi, idEdge=x.se;
if(idEdge==preEdge) continue;
if(!num[v]){
dfs(v,idEdge);
low[st]=min(low[st],low[v]);
} else {
low[st]=min(low[st],num[v]);
}
}
if(low[st]==num[st]){
++comp;
while(true){
ll v=scc.top(); scc.pop();
id[v]=comp;
if(v==st) break;
}
}
}
void dfs1(ll st,ll pre){
for(auto x:adj1[st]){
if(x.fi==pre) continue;
h[x.fi]=h[st]+1;
up[x.fi][0]=st;
par[x.fi]=st;
bripar[x.fi]=x.se;
child[st].pb(x.fi);
for(ll j=1;j<=LG;j++){
if(up[x.fi][j-1]) up[x.fi][j]=up[ up[x.fi][j-1] ][j-1];
else break;
}
dfs1(x.fi,st);
}
}
ll lca(ll u,ll v){
if(h[u]!=h[v]){
if(h[u]<h[v]) swap(u,v);
ll cnt=h[u]-h[v];
for(ll j=0;j<=LG;j++)
if((cnt>>j)&1) u=up[u][j];
}
if(u==v) return u;
for(ll j=LG;j>=0;j--)
if(up[u][j]!=up[v][j])
u=up[u][j],v=up[v][j];
return up[u][0];
}
void dfs2(ll st,ll pre){
for(ll x:child[st]){
dfs2(x,st);
goup[st]+=goup[x];
godown[st]+=godown[x];
cntup[ bripar[x] ] = goup[x];
cntdown[ bripar[x] ] = godown[x];
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);cout.tie(0);
cin>>n>>m;
for(i=1;i<=m;i++){
ll u,v; cin>>u>>v;
a[i]=u; b[i]=v;
adj[u].pb({v,i});
adj[v].pb({u,i});
ma[{min(u,v),max(u,v)}]++;
}
for(i=1;i<=n;i++)
if(!num[i]) dfs(i,0);
unordered_set<ll> s;
for(i=1;i<=m;i++){
if(id[a[i]]==id[b[i]] || ma[{min(a[i],b[i]),max(a[i],b[i])}]>1){
mark[i]=2;
} else {
adj1[id[a[i]]].pb({id[b[i]],i});
adj1[id[b[i]]].pb({id[a[i]],i});
s.insert(id[a[i]]);
s.insert(id[b[i]]);
}
}
vector<ll> roots;
for(ll x:s){
if(h[x]) continue;
roots.pb(x);
dfs1(x,x);
}
cin>>k;
for(i=1;i<=k;i++){
ll u,v; cin>>u>>v;
u=id[u]; v=id[v];
ll w=lca(u,v);
if(w==0) continue;
goup[u]++; goup[w]--;
godown[v]++; godown[w]--;
}
for(ll x:roots) dfs2(x,0);
for(i=1;i<=m;i++){
if(!mark[i]){
ll f = (h[id[a[i]]]<h[id[b[i]]]?0:1);
if(cntup[i] && !cntdown[i]) mark[i]=!f;
else if(cntdown[i] && !cntup[i]) mark[i]=f;
else mark[i]=2;
}
}
for(i=1;i<=m;i++){
if(mark[i]==0) cout<<'R';
else if(mark[i]==1) cout<<'L';
else cout<<'B';
}
return 0;
}
