#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long
// #define double long double
#define endl '\n'
#define fastIO ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
#define setmin(x, y) x = min((x), (y))
#define setmax(x, y) x = max((x), (y))
#define sqr(x) ((x) * (x))
#define fi first
#define se second
// mt19937 hdp(chrono::high_resolution_clock::now().time_since_epoch().count());
// int rand(int l, int r){return l + ((hdp() % (r - l + 1)) + r - l + 1) % (r - l + 1);}
const int NM = 1e6 + 5;
const int mod = 1e6 + 3;
const int inf = 1e9 + 1;
vector<int> g[NM];
vector<pair<int, pair<int, int>>> G[NM];
int n, m, N, tin[NM], low[NM], timer, comp[NM];
pair<int, int> e[NM];
map<pair<int, int>, bool> is_cau, ditme, deophaicau;
map<pair<int, int>, int> val;
void dfs(int u, int p)
{
tin[u] = low[u] = ++timer;
for (int v : g[u])
if (v != p)
{
if (tin[v])
setmin(low[u], low[v]);
else
{
dfs(v, u);
if (low[v] > tin[u] && !deophaicau[{u, v}])
is_cau[{u, v}] = 1;
setmin(low[u], low[v]);
}
}
}
bool vis[NM];
void cpr(int u)
{
comp[u] = N;
for (auto v : g[u])
{
if (is_cau[{u, v}] || is_cau[{v, u}])
{
if (comp[v])
{
G[N].push_back({comp[v], {u, v}});
G[comp[v]].push_back({N, {v, u}});
}
continue;
}
if (comp[v])
continue;
cpr(v);
}
}
void prep()
{
for (int i = 1; i <= n; i++)
if (!tin[i])
dfs(i, 0);
for (int i = 1; i <= n; i++)
if (!comp[i])
{
++N;
cpr(i);
}
}
int dp[NM], cur;
void DFS(int u)
{
vis[u] = 1;
for (auto v : G[u])
if (!vis[v.fi])
{
DFS(v.fi);
val[v.se] = dp[v.fi];
dp[u] += dp[v.fi];
}
}
pair<int, int> rev(pair<int, int> x)
{
return {x.se, x.fi};
}
signed main()
{
if (fopen("in.txt", "r")) {
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
}
fastIO
cin >> n >> m;
for (int i = 1; i <= m; i++)
{
int u, v;
cin >> u >> v;
e[i] = {u, v};
if (ditme[{u, v}] || ditme[{v, u}])
{
deophaicau[{u, v}] = deophaicau[{v, u}] = true;
continue;
}
ditme[{u, v}] = true;
ditme[{v, u}] = true;
g[u].push_back(v);
g[v].push_back(u);
}
prep();
int q;
cin >> q;
while (q--)
{
int u, v;
cin >> u >> v;
dp[comp[u]]++;
dp[comp[v]]--;
}
for (int i = 1; i <= N; i++)
if (!vis[i])
DFS(i);
for (int i = 1; i <= m; i++)
{
if (!val[e[i]] && !val[rev(e[i])])
cout << 'B';
else if (val[e[i]] < 0 || val[rev(e[i])] > 0)
cout << 'R';
else
cout << 'L';
}
}
