#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// https://codeforces.com/blog/entry/79148
class Timer: chrono::high_resolution_clock {
const time_point start_time;
public:
Timer(): start_time(now()) {}
rep elapsed_time() const {
return chrono::duration_cast<chrono::milliseconds>(now() - start_time).count();
}
} timer;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int n, m, q;
cin >> n >> m;
vector<vector<array<int, 3>>> graph(n + 1);
vector<int> depth(n + 1), low(n + 1, n), cnt(n + 1, 0);
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
graph[u].push_back({v, i, 1});
graph[v].push_back({u, i, 0});
}
cin >> q;
while (q--) {
int u, v;
cin >> u >> v;
cnt[v]++; cnt[u]--;
}
vector<bool> vis(n + 1, 0);
vector<char> ans(m, 0);
auto dfs = [&] (auto self, int u, int e)->bool {
vis[u] = 1;
for (auto &[v, id, dir] : graph[u]) {
if (id == e) {
continue;
}
if (vis[v]) {
ans[id] = 'B';
low[u] = min({low[u], depth[u], depth[v]});
}
else {
depth[v] = depth[u] + 1;
if (self(self, v, id) || !cnt[v]) {
ans[id] = 'B';
}
else {
ans[id] = (cnt[v] > 0) ^ dir ? 'L' : 'R';
}
cnt[u] += cnt[v];
low[u] = min(low[u], low[v]);
}
}
return low[u] < depth[u];
};
for (int i = 1; i <= n; i++) {
if (!vis[i]) {
depth[i] = 0;
dfs(dfs, i, -1);
}
}
for (auto &x : ans) {
cout << x;
}
return 0;
}
