#include<bits/stdc++.h>
#define MASK(i) (1 << (i))
#define pub push_back
#define all(v) v.begin(), v.end()
#define compact(v) v.erase(unique(all(v)), end(v))
#define pii pair<int,int>
#define fi first
#define se second
#define endl "\n"
#define sz(v) (int)(v).size()
#define dbg(x) "[" #x " = " << (x) << "]"
using namespace std;
template<class T> bool minimize(T& a, T b){if(a > b) return a = b, true;return false;}
template<class T> bool maximize(T& a, T b){if(a < b) return a = b, true;return false;}
typedef long long ll;
typedef long double ld;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r){return uniform_int_distribution<ll>(l, r)(rng);}
const int N = 1e5 + 15;
const int lg = 16;
int n, m, q;
pii edges[N];
vector<int> g[N];
int low[N], num[N], timerDFS;
int scc;
bool del[N];
stack<int> st;
int team[N];
int ans[N];
char luvna[] = {'B', 'R', 'L'};
void tarjan(int u, int pre_id){
low[u] = num[u] = ++timerDFS;
st.push(u);
for(int id : g[u]) if(id != pre_id){
int v = edges[id].fi ^ edges[id].se ^ u;
if(del[v]) continue;
if(num[v]) minimize(low[u], num[v]);
else{
tarjan(v,id);
minimize(low[u], low[v]);
}
}
if(low[u] == num[u]){
int v;
scc++;
do{
v = st.top(); st.pop();
del[v] = true;
team[v] = scc;
}while(v != u);
}
}
pii edgeSCC[N];
vector<int> adj[N];
int dp[N];
void dfsDP(int u, int pre_id){
del[u] = true;
for(int id : adj[u]) if(id != pre_id){
int v = edgeSCC[id].fi ^ edgeSCC[id].se ^ u;
dfsDP(v, id);
dp[u] += dp[v];
// u -> v -> v'
if(dp[v] > 0) ans[id] = (u == edges[id].se) ? 1 : 2;
else if(dp[v] < 0) ans[id] = (v == edges[id].se) ? 1 : 2;
}
}
void solve(){
cin >> n >> m;
for(int i = 1; i <= m; i++){
int u, v; cin >> u >> v;
edges[i] = {u,v};
g[u].push_back(i);
g[v].push_back(i);
}
for(int i = 1; i <= n; i++) if(!num[i]) tarjan(i,-1);
for(int i = 1; i <= m; i++){
int u = edges[i].fi, v = edges[i].se;
u = team[u], v = team[v];
if(u == v) continue;
edgeSCC[i] = {u,v};
adj[u].push_back(i);
adj[v].push_back(i);
}
cin >> q;
while(q--){
int u, v; cin >> u >> v;
u = team[u], v = team[v];
dp[u]++, dp[v]--;
}
fill(del + 1, del + 1 + scc, 0);
for(int i = 1; i <= scc; i++) if(!del[i]) dfsDP(i,-1);
for(int i = 1; i <= m; i++) cout << luvna[ans[i]];
}
signed main(){
ios_base::sync_with_stdio(NULL);
cin.tie(0); cout.tie(0);
#define task "task"
if(fopen(task".INP", "r")){
freopen(task".INP", "r", stdin);
freopen(task".OUT", "w", stdout);
}
int t; t = 1; //cin >> t;
while(t--) solve();
}
