#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<class T> using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef long long ll;
#define sep ' '
#define F first
#define S second
#define fastIO ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb push_back
#define kill(x) {cout << x << endl;return;}
#define sz(x) int(x.size())
#define SP(x) setprecision(x)
#define mod(x) (1ll*x%M+M)%M
#define p_q priority_queue
#define REP(i, k) for (int i = 0 ; i < k ; i ++)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e5+10;
const int lgn = 20;
int n, m, p;
int dp_b[N], dp_p[N];
int w[N];
int h[N];
bool vis[N];
int par[N][lgn];
map<pair<int, int>, char> ans;
vi adj[N];
void dfs(int v, int p=-1) {
vis[v] = true;
par[v][0] = p;
for(int i = 1 ; par[v][i-1] != -1 ; i ++) par[v][i] = par[par[v][i-1]][i-1];
h[v] = (p == -1 ? 0 : h[p] + 1);
for(int neigh: adj[v]) {
if (!vis[neigh]) {
dfs(neigh, v);
}
}
}
int lift_up(int u, int dis) {
for(int i = 0 ; i < lgn ; i ++) {
if ((dis>>i)&1) {
u = par[u][i];
}
}
return u;
}
int lca(int u, int v) {
if (h[u] < h[v]) swap(u, v);
int delta = h[u] - h[v];
u = lift_up(u, delta);
if (u == v) return u;
for(int i = lgn-1 ; i >= 0 ; i --) {
if (par[u][i] != par[v][i]) {
u = par[u][i], v = par[v][i];
}
}
return par[u][0];
}
void gfs(int v, int p = -1) {
vis[v] = true;
w[v] = h[v];
for(int neigh: adj[v]) {
if (!vis[neigh]) {
gfs(neigh, v);
dp_b[v] += dp_b[neigh];
dp_p[v] += dp_p[neigh];
w[v] = min(w[v], w[neigh]);
} else if (neigh != p) w[v] = min(w[v], h[neigh]);
}
if (p != -1 && w[v] == h[v]) {
assert(dp_b[v] >= 0 && dp_p[v] >= 0);
assert(dp_b[v] == 0 || dp_p[v] == 0);
if (dp_p[v]) {
ans[{p, v}] = 'R';
ans[{v, p}] = 'L';
}
if (dp_b[v]) {
ans[{p, v}] = 'L';
ans[{v, p}] = 'R';
}
}
}
void solve() {
memset(par, -1, sizeof par);
vector<pii> E;
cin >> n >> m;
for(int i = 0 ; i < m ; i ++) {
int u, v; cin >> u >> v; u--, v--;
adj[u].pb(v), adj[v].pb(u);
E.pb({u, v});
}
for(int i = 0 ; i < n ; i ++) {
if (!vis[i]) dfs(i);
}
cin >> p;
for(int i = 0 ; i < p ; i ++) {
int x, y; cin >> x >> y; x--, y--;
int z = lca(x, y);
assert(lift_up(x, h[x] - h[z]) == z && lift_up(y, h[y] - h[z]) == z);
dp_b[x]++, dp_p[y]++, dp_b[z]--, dp_p[z]--;
}
fill(vis, vis+n, false);
for(int i = 0 ; i < n ; i ++) {
if (!vis[i]) gfs(i);
}
for(auto [u, v]: E) {
if (ans.count({u, v})) {
cout << ans[{u, v}];
} else if (ans.count({v, u})) {
cout << ans[{v, u}];
} else
cout << 'B';
}
cout << endl;
}
// check MAXN
int32_t main() {
fastIO;
solve();
return 0;
}
