#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef string str;
const ll Mod = 1e9 + 7;
const int Maxn = 2e5 + 100;
ll par[Maxn];
ll get(ll u){
if(u == par[u]) return u;
return par[u] = get(par[u]);
}
void merge(ll u, ll v){
u = get(u); v = get(v);
par[u] = v;
}
vector<pll> G[Maxn];
vector<ll> H[Maxn];
vector< pll > ed, ed2;
ll ans[Maxn];
ll dep[Maxn];
ll DFS(ll u, ll d, ll p){
dep[u] = d;
ll hbk = d;
ll adj, res;
for(auto E : G[u]){
if(E.S == p) continue;
adj = E.F;
if(dep[adj]){
if(dep[adj] < d){merge(u, adj);
hbk = min(hbk, dep[adj]);
}
} else {
//cerr << "! " << adj << " " << u << '\n';
res = DFS(adj, d + 1, E.S);
if(res != d + 1) merge(u, adj);
else ed.pb({u, adj});
hbk = min(hbk, res);
}
}
return hbk;
}
ll sub[Maxn], va[Maxn], dep2[Maxn];
void dfs(ll u, ll p, ll d2){
dep2[u] = d2;
for(auto adj : H[u]){
if(dep2[adj] == 0){
dfs(adj, u, d2 + 1);
va[u] += va[adj];
}
}
}
map<pll, ll> mp;
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
iota(par, par + Maxn, 0);
ll n, m, p;
cin >> n >> m;
//assert(n == 5 && m == 6);
//cout << "BBRBBL\n";
//return 0;
ll u, v;
for(int i = 1; i <= m; i++){
cin >> u >> v;
mp[{u, v}] = i;
G[u].pb({v, i});
G[v].pb({u, i});
ed2.pb({u, v});
}
for(int i = 1; i <= n; i++) if(dep[i] == 0) DFS(i, 1, -1);
//for(int i = 1; i <= n; i++) cerr << get(i) << ' ';
cin >> p;
for(int i = 0; i < p; i++){
cin >> u >> v;
va[get(u)]++;
va[get(v)]--;
}
for(auto x : ed2){
if(get(x.F) == get(x.S)) continue;
H[get(x.F)].pb(get(x.S));
H[get(x.S)].pb(get(x.F));
}
for(int i = 1; i <= n; i++) if(get(i) == i && dep2[i] == 0) dfs(i, -1, 1);
for(auto x : ed2){
u = x.F; v = x.S;
if(get(x.F) == get(x.S)) continue;
assert(get(x.F) != get(x.S));
//cerr << "! " << x.F << ' ' << x.S << '\n';
//cerr << "!" << u << " " << v << '\n';
if(dep2[get(u)] < dep2[get(v)]) swap(u, v);
if(va[get(u)] == 0) continue;
if(va[get(u)] < 0) swap(u, v);
if(mp.count({u, v})) ans[mp[{u, v}]] = 1;
else {
assert( (mp[{v, u}] > 0) );
ans[mp[{v, u}]] = 2;
}
}
for(int i = 1; i <= m; i++) cout << "BRL"[ans[i]];
cout << '\n';
return 0;
}
/*
5 6
1 2
1 2
4 3
2 3
1 3
5 1
2
4 5
1 3
5 6
1 2
4 5
4 3
2 3
1 3
5 1
2
4 5
1 3
4 4
1 2
2 3
3 4
3 1
1
3 2
*/
