#include<bits/stdc++.h>
using namespace std;
#define int long long
#define INF 1e18
int n, m, k;
vector<vector<pair<int, int>>> g, g2;
vector<pair<int, int>> edges;
vector<int> num, low, comp;
int dfscnt = 0, compcnt = 0;
stack<int> s;
string ans;
vector<vector<int>> jump;
vector<int> dep, dp;
void tarjan(int u, int p) {
if (num[u] != -1) return;
// cout << u << " " << p << endl;
num[u] = low[u] = dfscnt;
dfscnt++;
s.push(u);
for (auto [v, x] : g[u]) {
if (v == p) continue;
if (num[v] == -1) {
tarjan(v, u);
low[u] = min(low[u], low[v]);
} else {
low[u] = min(low[u], num[v]);
}
}
if (num[u] == low[u]) {
int v = s.top();
while (v != u) {
s.pop();
comp[v] = compcnt;
v = s.top();
}
comp[v] = compcnt;
s.pop();
compcnt++;
}
}
void dfs(int u, int p, int d) {
jump[u][0] = p;
dep[u] = d;
for (auto [v, x] : g2[u]) {
if (v == p) continue;
dfs(v, u, d+1);
}
}
void pp() {
for (int j = 1; j < 30; j++) {
for (int i = 0; i < compcnt; i++) {
jump[i][j] = jump[jump[i][j-1]][j-1];
// cout << jump[i][j] << " ";
}
// cout << endl;
}
}
int lift(int a, int d) {
for (int i = 0; i < 30; i++) {
if ((1<<i)&d) {
a = jump[a][i];
}
}
return a;
}
int lca(int a, int b) {
if (dep[a] < dep[b]) swap(a, b);
a = lift(a, dep[a]-dep[b]);
for (int i = 29; i >= 0; i--) {
if (jump[a][i] != jump[b][i]) {
a = jump[a][i];
b = jump[b][i];
}
}
if (a != b) a = jump[a][0];
return a;
}
int dfs2(int u, int p) {
// cout << u << " " << p << endl;
int cnt = 0;
for (auto [v, x] : g2[u]) {
if (v == p) continue;
int tmp = dfs2(v, u);
if (tmp) {
// cout << "JAAA: " << v << " " << u << " _ " << edges[x].first << " " << edges[x].second << endl;
if (edges[x].first == u) ans[x] = 'R';
else ans[x] = 'L';
}
cnt += tmp;
}
cnt += dp[u];
// cout << u << " " << p << ": " << cnt << endl;
return cnt;
}
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n >> m;
edges = vector<pair<int, int>> (m);
g = vector<vector<pair<int, int>>> (n);
num = low = comp = vector<int> (n, -1);
for (int i = 0; i < m; i++) {
int a, b;
cin >> a >> b;
a--; b--;
edges[i] = {a, b};
g[a].push_back({b, i});
g[b].push_back({a, i});
ans.push_back('B');
}
tarjan(0, 0); //Find SCCs
/*
for (int i = 0; i < n; i++) {
cout << comp[i] << " ";
}
cout << endl;
*/
g2 = vector<vector<pair<int, int>>> (compcnt);
jump = vector<vector<int>> (compcnt, vector<int> (30, -1));
dep = vector<int> (compcnt, -1);
dp = vector<int> (compcnt, 0);
for (int i = 0; i < n; i++) {
for (auto [v, x] : g[i]) {
if (comp[i] == comp[v]) continue;
g2[comp[i]].push_back({comp[v], x});
}
}
for (int i = 0; i < m; i++) {
edges[i] = {comp[edges[i].first], comp[edges[i].second]};
}
dfs(0, 0, 0);
pp();
cin >> k;
for (int i = 0; i < k; i++) {
int a, b;
cin >> a >> b;
a--; b--;
int c = lca(comp[a], comp[b]);
dp[comp[a]]++;
dp[comp[b]]++;
dp[c] -= 2;
// cout << "C: " << c << endl;
}
dfs2(0, 0);
cout << ans << endl;
}
