#include <bits/stdc++.h>
using namespace std;
vector<int> adj[100005];
vector<pair<int, int>> cact[100005];
int dsu[100005], dt[100005][2];
int up[100005];
int reach[100005];
int tot[100005];
int ans[100005]; // 1 -> R, 2 -> L
int find(int n) {
if (dsu[n] == n) return n;
return dsu[n] = find(dsu[n]);
}
void merge(int a, int b) {
dsu[find(a)] = find(b);
}
void dfs(int n, int f, int d = 1) {
reach[n] = d;
for (int i:adj[n]) if (i != f) {
if (!reach[i]) dfs(i, n, d+1);
reach[n] = min(reach[n], reach[i]);
}
if (reach[n] < d) merge(n, f);
}
vector<int> order;
void c(int n, int f) {
for (auto [i, j]:cact[n]) if (i != f) {
up[i] = j;
c(i, n);
}
order.push_back(n);
}
int main() {
int N, M;
cin >> N >> M;
for (int i = 1; i <= M; i ++) {
cin >> dt[i][0] >> dt[i][1];
int a = dt[i][0], b = dt[i][1];
adj[a].push_back(b);
adj[b].push_back(a);
}
for (int i = 1; i <= N; i ++) dsu[i] = i;
dfs(1, 0);
for (int i = 1; i <= M; i ++) {
int a = dt[i][0], b = dt[i][1];
if (find(a) != find(b)) {
cact[find(a)].push_back({find(b), i});
cact[find(b)].push_back({find(a), i});
}
}
c(find(1), 0);
int Q;
cin >> Q;
while (Q --) {
int a, b;
cin >> a >> b;
if (find(a) != find(b)) {
tot[find(a)] ++, tot[find(b)] --;
}
}
for (int node:order) if (node != find(1)) {
if (tot[node] > 0) {
// move up
int a = dt[up[node]][0], b = dt[up[node]][1];
if (find(a) == node) ans[up[node]] = 1;
else ans[up[node]] = 2;
} else if (tot[node] < 0) {
int a = dt[up[node]][0], b = dt[up[node]][1];
if (find(a) == node) ans[up[node]] = 2;
else ans[up[node]] = 1;
}
}
for (int i = 1; i <= M; i ++) {
if (ans[i] == 1) cout << "R";
else if (ans[i] == 2) cout << "L";
else cout << "B";
}
}
