///In the name of GOD
#pragma GCC optimize("O2")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MXN = 1e5 + 10;
const ll INF = 1e18;
ll n, m, q;
ll Par[MXN], Sz[MXN], Min[MXN], dis[MXN], num[MXN];
vector<pair<ll, ll>> adj[MXN], G[MXN], Edge;
bool vis[MXN], mark[MXN];
string ANS;
ll Find(ll x){
return (Par[x] == x ? x : Par[x] = Find(Par[x]));
}
void Union(ll x, ll y){
x = Find(x), y = Find(y);
if(x == y) return;
if(Sz[x] < Sz[y]) swap(x, y);
Sz[x] += Sz[y], Par[y] = x;
}
void dfs(ll u, ll pid){
vis[u] = 1, Min[u] = INF;
for(auto Pr : adj[u]){
ll v, id; tie(v, id) = Pr;
if(id == pid) continue;
if(vis[v]){
Min[u] = min(Min[u], dis[v]);
ANS[id] = 'B';
continue;
}
dis[v] = dis[u] + 1;
dfs(v, id);
Min[u] = min(Min[u], Min[v]);
if(Min[v] <= dis[u]) Union(u, v), ANS[id] = 'B';
}
}
void DFS(ll u, ll par){
mark[u] = 1;
for(auto Pr : G[u]){
ll v, id; tie(v, id) = Pr;
if(v == par) continue;
DFS(v, u);
num[u] += num[v];
if(num[v] == 0) ANS[id] = 'B';
else{
ll from = (num[v] > 0 ? v : u);
ANS[id] = (from == Find(Edge[id - 1].first) ? 'R' : 'L');
}
}
}
int main(){
ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
cin >> n >> m;
ANS = "$";
for(int i = 1; i <= n; i ++) Par[i] = i, Sz[i] = 1;
for(int i = 1; i <= m; i ++){
ll u, v; cin >> u >> v;
adj[u].push_back({v, i});
adj[v].push_back({u, i});
Edge.push_back({u, v});
ANS += "N";
}
for(int i = 1; i <= n; i ++){
if(!vis[i]) dfs(i, 0);
}
for(int i = 0; i < m; i ++){
ll u, v; tie(u, v) = Edge[i];
u = Find(u), v = Find(v);
if(u == v){
assert(ANS[i + 1] == 'B');
continue;
}
assert(ANS[i + 1] == 'N');
G[u].push_back({v, i + 1});
G[v].push_back({u, i + 1});
}
cin >> q;
while(q --){
ll u, v; cin >> u >> v;
u = Find(u), v = Find(v);
num[u] ++, num[v] --;
}
for(int i = 1; i <= n; i ++){
if(Par[i] != i) continue;
if(!mark[i]) DFS(i, 0);
}
for(int i = 1; i <= m; i ++) assert(ANS[i] != 'N');
cout << ANS.substr(1, m) << '\n';
return 0;
}
/*!
HE'S AN INSTIGATOR,
ENEMY ELIMINATOR,
AND WHEN HE KNOCKS YOU BETTER
YOU BETTER LET HIM IN.
*/
//! N.N
