#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
const int INF = numeric_limits<int>::max() / 2;
vector<int> num, low, comp, used;
stack<int> s;
int dfs_count = 0;
int comp_count = 0;
vector<vector<int>> dir;
vector<int> in;
vector<int> out;
void tarjan_dfs(int current, int parent, vector<vector<pii>>& adj) {
num[current] = low[current] = dfs_count;
dfs_count++;
s.push(current);
for (pii neigh : adj[current]) {
if (used[neigh.second] == 1) continue;
used[neigh.second] = 1;
if (num[neigh.first] == INF) {
tarjan_dfs(neigh.first, current, adj);
low[current] = min(low[current], low[neigh.first]);
} else low[current] = min(low[current], num[neigh.first]);
}
if (num[current] == low[current]) {
while (s.top() != current) {
int top = s.top();
s.pop();
comp[top] = comp_count;
}
s.pop();
comp[current] = comp_count;
comp_count++;
}
}
int dir_dfs(int current, vector<int>& visited, vector<vector<int>>& adj) {
visited[current] = 1;
int incoming = in[current] - out[current];
for (int neigh : adj[current]) {
if (visited[neigh] == 0) {
int d = dir_dfs(neigh, visited, adj);
if (d < 0) {
dir[current][neigh] = -1;
dir[neigh][current] = 1;
} else if (d > 0) {
dir[current][neigh] = 1;
dir[neigh][current] = -1;
}
incoming += d;
}
}
return incoming;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie();
cout.tie();
int n, m;
cin >> n >> m;
vector<vector<pii>> adj(n);
vector<pii> streets;
for (int i = 0; i < m; i++) {
int a, b;
cin >> a >> b;
a--; b--;
adj[a].push_back(make_pair(b, i));
adj[b].push_back(make_pair(a, i));
streets.push_back(make_pair(a, b));
}
num = vector<int>(n, INF);
low = vector<int>(n);
comp = vector<int>(n);
used = vector<int>(m, 0);
for (int i = 0; i < n; i++) {
if (num[i] == INF) {
tarjan_dfs(i, i, adj);
}
}
vector<vector<int>> cadj(comp_count);
for (pii s : streets) {
if (comp[s.first] != comp[s.second]) {
cadj[comp[s.first]].push_back(comp[s.second]);
cadj[comp[s.second]].push_back(comp[s.first]);
}
}
in = vector<int>(comp_count, 0);
out = vector<int>(comp_count, 0);
int p;
cin >> p;
for (int i = 0; i < p; i++) {
int a, b;
cin >> a >> b;
a--; b--;
if (comp[a] != comp[b]) {
out[comp[a]]++;
in[comp[b]]++;
}
}
vector<int> visited(comp_count, 0);
dir = vector<vector<int>>(comp_count, vector<int>(comp_count, 0));
for (int i = 0; i < comp_count; i++) {
if (visited[i] == 0) dir_dfs(i, visited, cadj);
}
for (pii s : streets) {
if (comp[s.first] == comp[s.second] || dir[comp[s.first]][comp[s.second]] == 0) cout << 'B';
else if (dir[comp[s.first]][comp[s.second]] == 1) cout << 'R';
else cout << 'L';
}
return 0;
}
