#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
int n, m, in[N], low[N], timer = 1, sum[N], q, b[N], c[N];
vector<array<int, 2> > g[N], edg(N);
void dfs(int u, int p) {
in[u] = low[u] = timer++;
for(auto [v, id] : g[u]) {
if(p == id) continue;
if(in[v]) {
low[u] = min(low[u], in[v]);
} else {
dfs(v, id);
low[u] = min(low[u], low[v]);
if(low[v] > in[u]) b[id] = 1;
if(sum[v] == 0) c[id] = 0;
else if(sum[v] > 0) c[id] = 1;
else c[id] = -1;
if(edg[id][0] == u) c[id] *= 1;
else c[id] *= -1;
sum[u] += sum[v];
}
}
}
signed main() {
cin >> n >> m;
for(int i=1; i<=m; i++) {
int u, v; cin >> u >> v;
g[u].push_back({ v, i });
g[v].push_back({ u, i });
edg[i] = { u, v };
}
cin >> q;
while(q--) {
int u, v; cin >> u >> v;
sum[u]++;
sum[v]--;
}
for(int i=1; i<=n; i++)
if(!in[i]) dfs(i, -1);
for(int i=1; i<=m; i++) {
if(!b[i]) cout << 'B';
else cout << (c[i] == 1 ? 'L' : 'R');
}
}
