#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define int long long
const int maxn = 2e5 + 5;
int n, m, q;
vector<pll> adj[maxn];
vector<pll> nadj[maxn];
int scc[maxn], low[maxn], in[maxn], dfn = 0, cnt = 0;
int val[maxn];
pll ori[maxn];
stack<int> st;
void dfs(int pos, int pid){
low[pos] = in[pos] = ++dfn;
st.push(pos);
for(auto [x, id] : adj[pos]){
if(id == pid) continue;
if(in[x]) low[pos] = min(low[pos], in[x]);
else{
dfs(x, id);
low[pos] = min(low[pos], low[x]);
}
}
if(low[pos] >= in[pos]){
cnt++;
while(st.top() != pos){
scc[st.top()] = cnt;
st.pop();
}
scc[pos] = cnt;
st.pop();
}
}
void dfs2(int pos, int prev){
in[pos] = -1;
for(auto [x, id] : nadj[pos]){
if(x == prev) continue;
dfs2(x, pos);
if(val[x] > 0) ori[id] = {x, pos};
if(val[x] < 0) ori[id] = {pos, x};
val[pos] += val[x];
}
}
signed main(void){
fastio;
cin>>n>>m;
vector<pll> e;
for(int i = 0; i < m; i++){
int a, b;
cin>>a>>b;
a--, b--;
adj[a].eb(b, i);
adj[b].eb(a, i);
e.pb({a, b});
}
for(int i = 0; i < n; i++) if(!in[i]) dfs(i, -1);
for(int i = 0; i < n; i++){
for(auto [x, id] : adj[i]){
if(scc[i] != scc[x]){
nadj[scc[i]].eb(scc[x], id);
}
}
}
cin>>q;
for(int i = 0; i < q; i++){
int a, b;
cin>>a>>b;
a--, b--;
val[scc[a]] ++, val[scc[b]] --;
}
for(int i = 1; i <= cnt; i++) if(in[i] != -1) dfs2(i, -1);
for(int i = 0; i < m; i++){
if(ori[i].f == ori[i].s) cout<<'B';
else if(ori[i] == pll(scc[e[i].f], scc[e[i].s])) cout<<'R';
else cout<<'L';
}
cout<<"\n";
}
