#pragma GCC optimize("Ofast, unrool-loops")
#include <bits/stdc++.h>
using namespace std;
#define ll int
#define pll pair<int, int>
#define pb push_back
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
const ll N = 2e5 + 100;
const ll inf = 1e18;
const ll mod = 1e9 + 7;
const ll block = 480;
ll n,m,p,timer=0;
struct ccjv{ll v, prv, nxt;};
vector<pll>adj[N];
vector<ccjv>g[N];
ll cmp[N], low[N], num[N], b[N], pa[N];
pll edge[N];
ll cur = 0;
vector<pll>order;
map<pll,ll>dir;
void pre_dfs(ll u, ll par){
low[u] = num[u] = ++timer;
for(auto x : adj[u]){
ll v = x.F, idx = x.S;
if(idx == par) continue;
if(num[v]) low[u] = min(low[u], num[v]);
else{
pre_dfs(v, idx);
low[u] = min(low[u], low[v]);
if(low[v] == num[v]) {
//cout << "bridge" << ' ' << u << ' ' << v << '\n';
b[idx] = 1;
}
}
}
}
void dfs_cmp(ll u, ll par){
cmp[u] = cur;
for(auto x : adj[u]){
ll v = x.F, idx = x.S;
if(idx == par) continue;
if(b[idx]){
if(cmp[v]) g[cmp[u]].pb({cmp[v], u, v}), g[cmp[v]].pb({cmp[u], v, u});
}
else if(!cmp[v]) dfs_cmp(v, idx);
}
}
void dfs(ll u, ll par, ll b){
if(u == b){
for(auto x : order){
dir[{x.F, x.S}] = 1;
dir[{x.S, x.F}] = -1;
}
}
for(auto x : g[u]){
ll v = x.v;
if(v == par) continue;
order.pb({x.prv, x.nxt});
dfs(v, u, b);
order.pop_back();
}
}
void to_thic_cau(){
cin >> n >> m;
for(int i = 1; i <= m;i++){
ll u,v; cin >> u >> v;
edge[i] = {u, v};
adj[u].pb({v, i});
adj[v].pb({u, i});
}
for(int i = 1; i <= n;i++) if(!num[i]) pre_dfs(i, 0);
for(int i = 1; i <= n;i++){
if(!cmp[i]){
++cur;
dfs_cmp(i, 0);
}
}
cin >> p;
for(int i = 1; i <= p;i++){
ll a,b; cin >> a >> b;
dfs(cmp[a], 0, cmp[b]);
order.clear();
}
for(int i = 1; i <= m;i++){
if(!b[i]){
cout << 'B';
}
else{
if(!dir[{edge[i].F, edge[i].S}]) cout << 'B';
else if(dir[{edge[i].F, edge[i].S}] == 1) cout << 'R';
else cout << 'L';
}
}
cout << '\n';
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
ll tc = 1;
//cin >> tc;
while(tc--) to_thic_cau();
}
