#include <bits/stdc++.h>
using namespace std;
#define forsn(i, s, n) for (int i = int(s); i < int(n); i++)
#define forn(i, n) forsn(i, 0, n)
#define dforsn(i, s, n) for (int i = int(n) - 1; i >= int(s); i--)
#define dforn(i, n) dforsn(i, 0, n)
#define foreach(it, c) for (auto it = begin(c); it != end(c); it++)
#define sz(x) int(x.size())
#define all(x) begin(x), end(x)
#define pb push_back
#define eb emplace_back
using vi = vector<int>;
using ll = long long;
using ld = long double;
using vll = vector<ll>;
using ii = pair<int, int>;
#define fst first
#define snd second
const int MAX_N = 1e5 + 9;
int timer = 0;
stack<int> st;
bool vis[MAX_N];
int val[MAX_N], low[MAX_N];
vi adj[MAX_N];
vector<vi> comps;
void dfs(int u, int p = -1) {
vis[u] = true;
val[u] = low[u] = ++timer;
st.push(u);
for (int v : adj[u]) if (v != p) {
if (vis[v]) {
low[u] = min(low[u], val[v]);
} else {
dfs(v, u);
low[u] = min(low[u], low[v]);
if (low[v] >= val[u]) {
vi cmp{u};
while (cmp.empty() || cmp.back() != v) {
cmp.push_back(st.top());
st.pop();
}
comps.push_back(cmp);
}
}
}
}
const int MAX_K = 19;
vi g[2 * MAX_N];
int up[MAX_K][2 * MAX_N];
int depth[2 * MAX_N];
bool done[2 * MAX_N];
int parent[2 * MAX_N];
void dfs2(int u, int p = -1, int d = 0) {
up[0][u] = p, done[u] = true;
parent[u] = p, depth[u] = d;
for (int v : g[u]) if (v != p) {
dfs2(v, u, d + 1);
}
}
int lca(int u, int v) {
if (depth[u] < depth[v]) swap(u, v);
int diff = depth[u] - depth[v];
forn(i, MAX_K) if (diff >> i & 1) u = up[i][u];
if (u == v) return u;
dforn(i, MAX_K) if (up[i][u] != up[i][v]) {
u = up[i][u], v = up[i][v];
}
return up[0][u];
}
int dp1[2 * MAX_N], dp2[2 * MAX_N];
void dfs3(int u) {
done[u] = true;
for (int v : g[u]) if (v != parent[u]) {
if (!done[v]) dfs3(v);
dp1[u] += dp1[v];
dp2[u] += dp2[v];
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, m;
cin >> n >> m;
map<ii, int> id, cnt;
forn(i, m) {
int u, v;
cin >> u >> v;
--u, --v;
adj[u].pb(v);
adj[v].pb(u);
id[{u, v}] = i;
cnt[minmax(u, v)]++;
}
forn(u, n) if (!vis[u]) dfs(u);
vector<ii> bridges;
forn(i, sz(comps)) {
vi &cmp = comps[i];
if (sz(cmp) == 1) continue;
if (sz(cmp) == 2) {
int u = cmp[0], v = cmp[1];
if (cnt[minmax(u, v)] == 1) {
if (!id.count(ii{u, v})) swap(u, v);
bridges.eb(u, v);
g[u].pb(v), g[v].pb(u);
continue;
}
}
for (int u : cmp) {
g[n + i].pb(u);
g[u].pb(n + i);
}
}
forn(u, n + sz(comps)) {
if (!done[u]) dfs2(u);
}
forn(i, MAX_K - 1) forn(j, n + sz(comps)) {
if (up[i][j] == -1) up[i + 1][j] = -1;
else up[i + 1][j] = up[i][up[i][j]];
}
int p;
cin >> p;
forn(i, p) {
int u, v;
cin >> u >> v;
--u, --v;
int w = lca(u, v);
dp1[u]++, dp2[v]++;
dp1[w]--, dp2[w]--;
}
forn(u, n + sz(comps)) done[u] = false;
forn(u, n + sz(comps)) {
if (!done[u]) dfs3(u);
}
string ret(m, 'B');
for (auto [u, v] : bridges) {
int i = id[ii{u, v}];
if (parent[u] == v) {
if (dp1[u]) {
ret[i] = 'R';
} else if (dp2[u]) {
ret[i] = 'L';
}
} else {
assert(parent[v] == u);
if (dp1[v]) {
ret[i] = 'L';
} else if (dp2[v]) {
ret[i] = 'R';
}
}
}
cout << ret << '\n';
return 0;
}
