#include <bits/stdc++.h>
using namespace std;
struct Edge
{
unsigned v, i;
bool as_given;
Edge(unsigned v_, unsigned i_, bool as_given_)
{
v = v_, i = i_, as_given = as_given_;
}
};
vector<vector<Edge>> g;
vector<int> r;
vector<unsigned> y, l;
vector<bool> visited;
string orientation;
unsigned orient_edges(unsigned u, Edge p = Edge(-1, -1, 0), unsigned i = 0)
{
visited[u] = 1;
y[u] = l[u] = i++;
for (Edge const &e : g[u])
{
if (!visited[e.v])
{
i = orient_edges(e.v, e, i);
r[u] += r[e.v];
l[u] = min(l[u], l[e.v]);
}
if (e.i != p.i)
{
if (l[e.v] > y[u] && r[e.v])
orientation[e.i] = ((r[e.v] > 0) ^ !e.as_given) ? 'L' : 'R';
else
orientation[e.i] = 'B';
l[u] = min(l[u], y[e.v]);
}
}
return i;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
size_t n, m;
cin >> n >> m;
g = vector<vector<Edge>>(n);
r = vector<int>(n, 0);
y = vector<unsigned>(n);
l = vector<unsigned>(n);
visited = vector<bool>(n, 0);
orientation.resize(m);
for (unsigned i = 0; i < m; i++)
{
unsigned u, v;
cin >> u >> v;
g[u - 1].emplace_back(v - 1, i, 1);
g[v - 1].emplace_back(u - 1, i, 0);
}
size_t p;
cin >> p;
for (size_t i = 0; i < p; i++)
{
unsigned u, v;
cin >> u >> v;
r[u - 1]++;
r[v - 1]--;
}
for (unsigned i = 0; i < n; i++)
if (!visited[i])
orient_edges(i);
cout << orientation << '\n';
}
