// I_Love_LPL 11m
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int N = 3e5 + 5;
long long mod = 1000007;
const int lim = 4e5 + 5;
const int lg = 20;
const int base = 311;
const long double eps = 1e-6;
ll ans = 0, timer = 0, cnt = 0;
vector<pair<ll, ll>> node[N];
vector<ll> adj[N];
ll ids[N], low[N], in[N], vis[N], s[N], e[N], sz[N], dep[N], dp[N][lg + 1], grp[N];
char res[N];
ll root;
vector<ll> st;
map<pair<ll, ll>, ll> dir, mem;
void dfs3(ll u, ll p){
vis[u] = 1;
for (auto j : adj[u]){
if (j == p) continue;
dfs3(j, u);
sz[u] += sz[j];
}
if (sz[u] < 0){
if (dir[{p, u}]) res[mem[{p, u}]] = 'R';
else res[mem[{p, u}]] = 'L';
} else if (sz[u] > 0) {
if (dir[{p, u}]) res[mem[{p, u}]] = 'L';
else res[mem[{p, u}]] = 'R';
}
}
ll LCA(ll u, ll v){
if (dep[u] > dep[v]) swap(u, v);
ll dist = dep[v] - dep[u];
for (int i = 0; i <= lg; i++){
if (dist & (1 << i)){
v = dp[v][i];
}
}
if (u == v) return u;
for (int i = lg; i >= 0; i--){
if (dp[v][i] != dp[u][i]){
v = dp[v][i];
u = dp[u][i];
}
}
return dp[v][0];
}
void dfs2(ll u, ll p){
vis[u] = 1;
for (int i = 1; i <= lg; i++) dp[u][i] = dp[dp[u][i - 1]][i - 1];
for (auto j : adj[u]){
if (j == p) continue;
dep[j] = dep[u] + 1;
dp[j][0] = u;
dfs2(j, u);
}
}
void dfs(ll u, ll p){
vis[u] = 1;
timer++;
ids[u] = low[u] = timer;
st.push_back(u);
in[u] = 1;
for (auto j : node[u]){
if (j.second == p) continue;
if (in[j.first]){
low[u] = min(low[u], ids[j.first]);
} else if (vis[j.first] == 0){
dfs(j.first, j.second);
low[u] = min(low[u], low[j.first]);
}
}
if (low[u] == ids[u]){
ans++;
while (true){
ll x = st.back();
grp[x] = ans;
in[x] = 0;
st.pop_back();
low[x] = low[u];
if (x == u) break;
}
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
if (fopen("tests.inp", "r")){
freopen("test.inp", "r", stdin);
freopen("test.out", "w", stdout);
}
ll n, m, p;
cin >> n >> m;
for (int i = 1; i <= m; i++){
cin >> s[i] >> e[i];
node[s[i]].push_back({e[i], i});
node[e[i]].push_back({s[i], i});
res[i] = '?';
}
for (int i = 1; i <= n; i++){
if (vis[i]) continue;
root = i;
dfs(i, 0);
}
memset(vis, 0, sizeof(vis));
for (int i = 1; i <= m; i++){
ll u = grp[s[i]], v = grp[e[i]];
if (u == v) continue;
if (mem[{u, v}] == 0){
adj[u].push_back(v);
adj[v].push_back(u);
mem[{u, v}] = i;
mem[{v, u}] = i;
dir[{u, v}] = 1;
dir[{v, u}] = 0;
}
}
for (int i = 1; i <= ans; i++){
if (vis[i]) continue;
dfs2(i, i);
}
cin >> p;
for (int i = 1; i <= p; i++){
ll u, v;
cin >> u >> v;
u = grp[u];
v = grp[v];
ll lca = LCA(grp[u], grp[v]);
sz[u] += 1;
sz[lca] -= 1;
sz[v] -= 1;
sz[lca] += 1;
}
memset(vis, 0, sizeof(vis));
for (int i = 1; i <= ans; i++){
if (vis[i]) continue;
dfs3(i, i);
}
for (int i = 1; i <= m; i++){
if (res[i] == '?') res[i] = 'B';
cout << res[i];
}
}
/*
Ans:
Out:
*/
