#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair
//#define endl '\n'
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
typedef long long ll;
const int MOD = 1e9 + 7;
const int N = 2e5 + 3e2;
template<typename T>
struct fenwick{
vector<T> f;
fenwick(int n){
f.resize(n + 2);
}
fenwick(){};
void init(int n){
f.resize(n + 2);
}
void add(int i, T val){
i++;
while (i < (int)f.size()){
f[i] += val;
i += -i & i;
}
}
void add(int l, int r, T val){
add(l, val);
add(r + 1, -val);
}
T get(int i){
i++;
T res = 0;
while (i > 0){
res += f[i];
i -= -i & i;
}
return res;
}
T get(int l, int r){
if (l > r) return 0;
return get(r) - get(l - 1);
}
};
vector<pair<int, int>> g[N];
int fup[N], tin[N], timer;
bool used[N], bridge[N];
void dfs0(int v, int p){
tin[v] = fup[v] = ++timer;
used[v] = true;
for (auto [c, i] : g[v]){
if (c == p) continue;
if (!used[c]){
dfs0(c, v);
fup[v] = min(fup[v], fup[c]);
if (fup[c] > tin[v]){
bridge[i] = true;
}
} else {
fup[v] = min(fup[v], tin[c]);
}
}
}
int id[N];
void dfs1(int v, int _id){
used[v] = true;
id[v] = _id;
for (auto [c, i] : g[v]){
if (!used[c] && !bridge[i]) dfs1(c, _id);
}
}
vector<int> g2[N];
int up[N][18];
int tout[N];
void dfs2(int v, int p){
tin[v] = tout[v] = ++timer;
up[v][0] = p;
for (int i = 1; i < 18; i++){
up[v][i] = up[up[v][i - 1]][i - 1];
}
for (int c : g2[v]){
if (c != p){
dfs2(c, v);
tout[v] = tout[c];
}
}
}
bool upper(int p, int v){
return tin[p] <= tin[v] && tout[v] <= tout[p];
}
int lca(int u, int v){
if (upper(u, v)) return u;
if (upper(v, u)) return v;
for (int i = 17; i >= 0; i--){
if (!upper(up[u][i], v)) u = up[u][i];
}
return up[u][0];
}
vector<int> upwards[N], downwards[N];
fenwick<int> fu(N), fd(N);
set<pair<int, int>> must;
void dfs3(int v, int p){
for (int x : upwards[v]) fu.add(tin[x], 1);
for (int x : downwards[v]) fd.add(tin[x], 1);
for (int c : g2[v]){
if (c != p){
if (fu.get(tin[c], tout[c])) must.insert(MP(c, v));
if (fd.get(tin[c], tout[c])) must.insert(MP(v, c));
dfs3(c, v);
}
}
}
void solve(){
int n, m;
cin >> n >> m;
vector<pair<int, int>> edges;
for (int i = 0; i < m; i++){
int u, v;
cin >> u >> v;
g[u].emplace_back(v, i);
g[v].emplace_back(u, i);
edges.emplace_back(u, v);
}
for (int i = 1; i <= n; i++){
if (!used[i]) dfs0(i, -1);
}
map<pair<int, int>, int> mpe;
for (int i = 0; i < m; i++){
auto [u, v] = edges[i];
if (u > v) swap(u, v);
if (mpe.find(MP(u, v)) != mpe.end()){
bridge[i] = false;
bridge[mpe[(MP(u, v))]] = false;
} else {
mpe[MP(u, v)] = i;
}
}
fill(used + 1, used + n + 1, false);
int id_cnt = 0;
for (int i = 1; i <= n; i++){
if (!used[i]) dfs1(i, ++id_cnt);
}
for (int i = 0; i < m; i++){
auto [u, v] = edges[i];
u = id[u], v = id[v];
if (bridge[i]){
g2[u].emplace_back(v);
g2[v].emplace_back(u);
}
}
timer = 0;
for (int i = 1; i <= id_cnt; i++){
if (up[i][0] == 0){
dfs2(i, i);
}
}
int q;
cin >> q;
while (q--){
int u, v;
cin >> u >> v;
u = id[u], v = id[v];
int x = lca(u, v);
if (x != u) upwards[x].push_back(u);
if (x != v) downwards[x].push_back(v);
}
for (int i = 1; i <= id_cnt; i++){
if (up[i][0] == i) dfs3(i, i);
}
for (int i = 0; i < m; i++){
auto [u, v] = edges[i];
u = id[u], v = id[v];
char ch = 'B';
if (must.find(MP(u, v)) != must.end()) ch = 'R';
if (must.find(MP(v, u)) != must.end()) ch = 'L';
cout << ch;
}
cout << endl;
}
int main(){
clock_t startTime = clock();
ios_base::sync_with_stdio(false);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int test_cases = 1;
// cin >> test_cases;
for (int test = 1; test <= test_cases; test++){
// cout << (solve() ? "YES" : "NO") << endl;
solve();
}
cerr << "Time: " << int((double) (clock() - startTime) / CLOCKS_PER_SEC * 1000) << " ms" << endl;
return 0;
}
