#include <bits/stdc++.h>
#define fi first
#define se second
#define int long long
using namespace std;
using ll = long long;
using ii = pair<int,int>;
using pii = pair<int,ii>;
using aa = array<int,5>;
const int N = 1e5+5;
const int MAX = 100;
const int INF = 1e9;
const int MOD = 998244353;
int n,m,u,v,q,cnt = 0,timer = 0;
int num[N],low[N],scc[N],pre[N];
ii p[N];
bool vis[N];
stack<int> st;
vector <int> adj[N],g[N];
map<ii,int> mp;
void dfs(int u,int p){
num[u] = low[u] = ++timer;
st.push(u);
for(int v : adj[u]) {
if (vis[v] || v == p) continue;
if (!num[v]){
dfs(v,u);
low[u] = min(low[u],low[v]);
} else low[u] = min(low[u],num[v]);
}
if (low[u] == num[u]){
int v = -1;
cnt++;
while (v != u){
v = st.top();
vis[v] = 1;
scc[v] = cnt;
st.pop();
}
}
}
void dp(int u,int p){
vis[u] = 1;
for (int it : g[u]){
if (vis[it]) continue;
dp(it,u);
pre[u] += pre[it];
}
if (pre[u] > 0) mp[{u,p}] = 1;
else if (pre[u] < 0) mp[{p,u}] = 1;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
cin >> n >> m;
for (int i = 1; i <= m; i++){
cin >> u >> v;
p[i] = {u,v};
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int i = 1; i <= n; i++){
if (!num[i]) dfs(i,0);
}
for (int i = 1; i <= n; i++){
for (int x : adj[i]){
if (scc[i] == scc[x]) continue;
g[scc[i]].push_back(scc[x]);
}
}
memset(vis,0,sizeof vis);
cin >> q;
for (int i = 1; i <= q; i++){
cin >> u >> v;
pre[scc[u]]++;
pre[scc[v]]--;
}
for (int i = 1; i <= cnt; i++){
if (!vis[i]) dp(i,0);
}
for (int i = 1; i <= m; i++){
tie(u,v) = p[i];
if (scc[u] == scc[v]){
cout << "B";
continue;
}
if (mp[{scc[u],scc[v]}]) cout << "R";
else if (mp[{scc[v],scc[u]}]) cout << "L";
else cout << "B";
}
return 0;
}
