#include <bits/stdc++.h>
/*
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC target ("avx2")
*/
using namespace std;
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
*/
#define F first
#define S second
#define pb push_back
#define md(a) (a%mod)
#define all(a) a.begin(), a.end()
#define MP make_pair
#define lc (id<<1)
#define rc (lc|1)
#define mid (l+r)/2
#define kill(a) cout << a << "\n", exit(0)
#define SZ(a) (ll)a.size()
typedef pair<int,int> pii;
typedef pair<long long ,long long> pll;
typedef long long ll;
typedef long double ld;
typedef vector<vector<ll>> matrix;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll const maxn=2e5+10, mod=1e9+7, INF=1e18, LOG=31, sq=65;
ll poww(ll a, ll b, ll mod) {
if (b == 0) return 1;
return 1 * poww(1 * a * a % mod, b / 2, mod) * ((b % 2 == 1) ? a : 1) % mod;
}
ll n, m, dp[maxn], dp2[maxn];
vector<pll> g[maxn];
char ans[maxn];
bool vis[maxn], Vvis[maxn];
void DFS(ll v)
{
Vvis[v]=1;
for(auto [u, i]:g[v])
{
if(vis[abs(i)]) continue;
vis[abs(i)]=1;
if(!Vvis[u])
{
DFS(u);
if(dp2[u]>0||dp[u]==0) ans[abs(i)]='B';
else ans[abs(i)]=((dp[u]<0)^(i>0))?'L':'R';
dp[v]+=dp[u];
dp2[v]+=dp2[u];
}
else{
ans[abs(i)]='B';
dp2[v]++;
dp2[u]--;
}
}
}
int main()
{
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin>>n>>m;
for(ll i=1;i<=m;i++)
{
ll v, u;
cin>>v>>u;
g[v].pb({u, i});
g[u].pb({v, -i});
}
ll q;
cin>>q;
while(q--)
{
ll v, u;
cin>>v>>u;
dp[v]++;
dp[u]--;
}
DFS(1);
for(ll i=1;i<=m;i++) cout<<ans[i];
cout<<"\n";
return 0;
}
