#include <bits/stdc++.h>
#define long long long
#define vi vector<int>
#define vvi vector<vi>
using namespace std;
const int N = (int) 1E5;
int t[N], c;
vector<int> a[N];
/*
namespace BCC {
int n, timer = 0;
vi tin(N, -1), low(N);
stack<int> s;
vvi adj(N);
inline void add(int a, int b){
adj[a].emplace_back(b);
adj[b].emplace_back(a);
return;
}
inline void dfs(int v, int p){
tin[v] = low[v] = ++timer;
for(int &u : adj[v]){
if(u == p) continue;
if(tin[u] != -1){
low[v] = min(low[v], tin[u]);
}
else{
dfs(u, v);
low[v] = min(low[v], low[u]);
}
}
if(low[v] == tin[v]){
while(s.top() != v){
t[s.top()] = c;
a[c].emplace_back(s.top());
s.pop();
}
t[s.top()] = c;
a[c++].emplace_back(s.top());
s.pop();
}
return;
}
inline void solve(int p){
n = p;
for(int i = 0; i < n; i++){
if(tin[i] == -1){
dfs(i, i);
}
}
return;
}
};
*/
namespace BCC {
int n;
int d[N], f[N], x;
vector<int> e[N];
stack<int> s;
void add(int u, int v) {
e[u].push_back(v);
e[v].push_back(u);
}
void DFS(int u, int p = 0 - 1) {
d[u] = x;
x = x + 1;
f[u] = d[u];
s.push(u);
int o = 0;
for (auto v : e[u]) {
if (v == p && o == 0) {
o = 1;
continue;
}
if (d[v] < 0) {
DFS(v, u);
f[u] = min(f[u], f[v]);
} else {
f[u] = min(f[u], d[v]);
}
}
if (f[u] == d[u]) {
while (s.top() != u) {
t[s.top()] = c;
a[c].push_back(s.top());
s.pop();
}
t[s.top()] = c;
a[c].push_back(s.top());
s.pop();
c = c + 1;
}
}
void solve(int p) {
n = p;
fill(d, d + n, 0 - 1);
for (int u = 0; u < n; u++) {
if (d[u] < 0) {
DFS(u);
}
}
}
};
int n, m;
vector<array<int, 3>> e[N];
int k;
char s[N];
int p[N], d[N];
vector<array<int, 3>> E[N];
void DFS(int u) {
for (auto A : E[u]) {
int v = A[0], i = A[1], x = A[2];
if (v != p[u]) {
p[v] = u;
DFS(v);
if (d[v] > 0) {
s[i] = (x > 0 ? 'R' : 'L');
}
if (d[v] < 0) {
s[i] = (x > 0 ? 'L' : 'R');
}
d[u] = d[u] + d[v];
}
}
if (p[u] < 0) {
assert(d[u] == 0);
}
}
void solve() {
cin >> n >> m;
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
u = u - 1, v = v - 1;
e[u].push_back({v, i, 0});
e[v].push_back({u, i, 1});
BCC::add(u, v);
}
BCC::solve(n);
for (int u = 0; u < n; u++) {
for (auto A : e[u]) {
int v = A[0], i = A[1], x = A[2];
if (t[u] != t[v] && x == 0) {
E[t[u]].push_back({t[v], i, 0});
E[t[v]].push_back({t[u], i, 1});
}
}
}
cin >> k;
for (int i = 0; i < k; i++) {
int u, v;
cin >> u >> v;
u = u - 1, v = v - 1;
d[t[u]] = d[t[u]] + 1;
d[t[v]] = d[t[v]] - 1;
}
fill(s, s + m, 'B');
fill(p, p + c, 0 - 1);
for (int u = 0; u < c; u++) {
if (p[u] < 0) {
DFS(u);
}
}
for (int i = 0; i < m; i++) {
cout << s[i];
}
cout << "\n";
}
int main() {
ios::sync_with_stdio(0);
cin.tie(nullptr);
int t;
t = 1;
for (int i = 0; i < t; i++) {
solve();
}
return 0;
}
