#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
using ll = long long;
const ll MAXN = 100005;
const ll MAXM = 100005;
vector<tuple<ll, ll, char>> edges[MAXN];
bool vis[MAXN];
ll tin[MAXN], low[MAXN];
bool is_bridge[MAXM];
ll timer = 0;
ll who[MAXN];
ll comp_num = 1;
stack<ll> st;
void find_bridges(ll v, ll peid) {
if (vis[v]) return;
vis[v] = 1;
tin[v] = low[v] = timer++;
st.push(v);
for (auto[u, id, dir] : edges[v]) {
if (id == peid) continue;
if (!vis[u]) {
find_bridges(u, id);
low[v] = min(low[v], low[u]);
if (low[u] > tin[v]) {
is_bridge[id] = 1;
while (1) {
ll x = st.top();
st.pop();
who[x] = comp_num;
if (x == u) break;
}
comp_num++;
}
} else {
low[v] = min(low[v], tin[u]);
}
}
}
vector<tuple<ll, ll, char>> tecc_edges[MAXN];
tuple<ll, ll, char> parent[MAXN];
ll depth[MAXN];
string ans;
struct DSU {
vector<ll> p;
DSU(ll n) {
p.resize(n);
iota(all(p), 0);
}
ll get(ll v) {
if (p[v] == v) return v;
return p[v] = get(p[v]);
}
void unite(ll par, ll v) {
par = get(par);
v = get(v);
if (par == v) return;
p[v] = par;
}
};
void dfs(ll v, ll lca, bool up, DSU& dsu) {
if (depth[v] <= depth[lca]) return;
auto[u, id, dir] = parent[v];
if (dsu.get(v) == v) {
dsu.unite(u, v);
dfs(u, lca, up, dsu);
} else {
dfs(dsu.get(v), lca, up, dsu);
}
if (up) ans[id] = dir == 'L' ? 'R' : 'L';
else ans[id] = dir;
}
struct LCA {
struct RMQ {
vector<pair<ll, ll>> nodes;
ll size = 1;
RMQ(ll n) {
while (size < n) size*=2;
nodes.assign(2*size, {1e18, 1e18});
}
void build(vector<pair<ll, ll>>& a, ll x, ll lx, ll rx) {
if (rx-lx == 1) {
if (lx < a.size()) {
nodes[x] = a[lx];
}
return;
}
ll m = (lx+rx)/2;
build(a, 2*x+1, lx, m);
build(a, 2*x+2, m, rx);
nodes[x] = min(nodes[2*x+1], nodes[2*x+2]);
}
void build(vector<pair<ll, ll>>& a) {
build(a, 0, 0, size);
}
pair<ll, ll> query(ll l, ll r, ll x, ll lx, ll rx) {
if (lx >= l && rx <= r) return nodes[x];
if (rx <= l || lx >= r) return {1e18, 1e18};
ll m = (lx+rx)/2;
return min(query(l, r, 2*x+1, lx, m), query(l, r, 2*x+2, m , rx));
}
pair<ll, ll> query(ll l, ll r) {
return query(l, r, 0, 0, size);
}
};
vector<pair<ll, ll>> euler;
vector<ll> first;
RMQ rmq;
LCA(ll root, ll n) : rmq(2*n) {
first.assign(n, -1);
dfs(root, -1, 0);
rmq.build(euler);
}
void dfs(ll v, ll p, ll d) {
euler.push_back({d, v});
if (first[v] == -1) first[v] = euler.size()-1;
depth[v] = d;
for (auto[u, id, dir] : tecc_edges[v]) {
if (u == p) continue;
dfs(u, v, d+1);
euler.push_back({d, v});
parent[u] = {v, id, dir};
}
}
ll get(ll v, ll u) {
if (first[v] > first[u]) swap(v, u);
return rmq.query(first[v], first[u]+1).se;
}
};
void solve() {
ll n, m;
cin >> n >> m;
for (ll i = 0; i < m; i++) {
ll v, u;
cin >> v >> u;
v--, u--;
edges[v].push_back({u, i, 'R'});
edges[u].push_back({v, i, 'L'});
}
for (ll v = 0; v < n; v++) tin[v] = low[v] = 1e18;
for (ll v = 0; v < n; v++) {
if (vis[v]) continue;
find_bridges(v, -1);
}
for (ll v = 0; v < n; v++) {
for (auto[u, id, dir] : edges[v]) {
if (who[v] == who[u]) continue;
tecc_edges[who[v]].push_back({who[u], id, dir});
}
}
LCA lca(0, comp_num);
ans.assign(m, 'B');
DSU dsu(comp_num);
ll q; cin >> q;
while (q--) {
ll a, b;
cin >> a >> b;
a--, b--;
a = who[a], b = who[b];
ll c = lca.get(a, b);
dfs(a, c, 1, dsu);
dfs(b, c, 0, dsu);
}
cout << ans << '\n';
}
int main() {
// freopen("promote.in", "r", stdin);
// freopen("promote.out", "w", stdout);
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
solve();
}
