//In The Name of Allah
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair < int , int > pii;
typedef pair < ll , ll > pll;
#define X first
#define Y second
#define mp make_pair
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define Sz(x) (int)(x.size())
const int N = 1e5 + 10;
const ll mod = 1e9 + 7;
const int inf = 1e9 + 10;
int ea[N], eb[N], mark[N], h[N], dp[N], par[N], sz[N], sum[N];
vector < pii > adj[N], Adj[N];
vector < pair < pii , int > > fut;
char ans[N];
int getPar(int v){
return par[v] == v ? v : par[v] = getPar(par[v]);
}
void merge(int u, int v){
u = getPar(u);
v = getPar(v);
if (u == v)
return;
if (sz[v] < sz[u])
swap(u, v);
par[u] = v;
sz[v] += sz[u];
}
void cutDFS(int v, int p){
mark[v] = 1;
dp[v] = inf;
for (pii e : adj[v]){
int u = e.X, id = e.Y;
if (id == p)
continue;
if (mark[u]){
merge(u, v);
ans[id] = 'B';
dp[v] = min(dp[v], h[u]);
}
else{
h[u] = h[v] + 1;
cutDFS(u, id);
dp[v] = min(dp[v], dp[u]);
if (h[v] < dp[u]){
fut.pb(mp(mp(u, v), id));
}
else{
merge(u, v);
ans[id] = 'B';
}
}
}
}
void calDFS(int v){
mark[v] = 1;
for (pii e : Adj[v]){
int u = e.X, id = e.Y;
if (mark[u])
continue;
calDFS(u);
sum[v] += sum[u];
if (sum[u] == 0){
ans[id] = 'B';
}
if (sum[u] > 0){
if (getPar(ea[id]) == u)
ans[id] = 'R';
else
ans[id] = 'L';
}
if (sum[u] < 0){
if (getPar(ea[id]) == v)
ans[id] = 'R';
else
ans[id] = 'L';
}
}
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, m;
cin >> n >> m;
for (int i = 0; i < m; i ++){
cin >> ea[i] >> eb[i];
adj[ea[i]].pb(mp(eb[i], i));
adj[eb[i]].pb(mp(ea[i], i));
}
for (int i = 0; i < N; i ++)
par[i] = i, sz[i] = 1;
for (int i = 1; i <= n; i ++){
if (!mark[i])
cutDFS(i, -1);
}
for (auto x : fut){
int u = x.X.X;
int v = x.X.Y;
int id = x.Y;
u = getPar(u);
v = getPar(v);
Adj[u].pb(mp(v, id));
Adj[v].pb(mp(u, id));
}
memset(mark, 0, sizeof mark);
int q;
cin >> q;
for (int i = 0; i < q; i ++){
int x, y;
cin >> x >> y;
x = getPar(x);
y = getPar(y);
sum[x] ++;
sum[y] --;
}
for (int i = 1; i <= n; i ++)
if (!mark[i])
calDFS(i);
for (int i = 0; i < m; i ++)
cout << ans[i];
return 0;
}
