#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
int tin[maxn], low[maxn], scc[maxn], dp[maxn], edge[maxn][2], vis[maxn], timeDfs;
char ans[maxn];
stack<int> st;
vector<int> adj[maxn], g[maxn];
void dfs0(int u, int p){
st.push(u);
tin[u] = low[u] = ++timeDfs;
for(int id: g[u]){
if(id == p) continue;
int v = edge[id][0] ^ edge[id][1] ^ u;
if(!tin[v]) dfs0(v, id);
low[u] = min(low[u], low[v]);
}
if(low[u] == tin[u]){
while(true){
int node = st.top();
st.pop();
scc[node] = u;
if(node == u) return;
}
}
}
void dfs1(int x, int p){
vis[x] = true;
for(int id: adj[x]){
int v = edge[id][0] ^ edge[id][1] ^ x;
if(!vis[v]){
dfs1(v, id);
dp[x] += dp[v];
}
}
if(p != -1){
if(!dp[x]) ans[p] = 'B';
else{
if(dp[x] < 0) ans[p] = (x == edge[p][1] ? 'R' : 'L');
else ans[p] = (x == edge[p][0] ? 'R' : 'L');
}
}
return;
}
void solve(){
int n, m; cin >> n >> m;
for(int i = 1; i <= m; i++){
cin >> edge[i][0] >> edge[i][1];
g[edge[i][0]].push_back(i);
g[edge[i][1]].push_back(i);
}
for(int i = 1; i <= n; i++){
if(!tin[i]) dfs0(i, -1);
}
for(int i = 1; i <= m; i++){
int u = edge[i][0], v = edge[i][1];
if(scc[u] != scc[v]){
adj[scc[u]].push_back(i);
adj[scc[v]].push_back(i);
edge[i][0] = scc[u];
edge[i][1] = scc[v];
}
else ans[i] = 'B';
}
int q; cin >> q;
for(int i = 1; i <= q; i++){
int x, y; cin >> x >> y;
dp[scc[x]]++;
dp[scc[y]]--;
}
for(int i = 1; i <= n; i++){
if(!vis[i]) dfs1(i, -1);
}
for(int i = 1; i <= m; i++) cout << ans[i];
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
solve();
}
