#include <bits/stdc++.h>
#define all(s) s.begin(), s.end()
#define lb(s, a) lower_bound(all(s), (a)) - s.begin()
#define ii pair <int, int>
#define fi first
#define se second
using namespace std;
typedef long long ll;
const int ar = 2e5+2;
const ll mod = 1e9+7;
const int oo = 1e9;
int n, m;
int timeDfs = 0, scc = 0;
int low[ar], num[ar];
int id[ar];
bool vs[ar], bridge[ar];
struct set3 {
int v, i, t;
};
vector <set3> g[ar], adj[ar];
void dfs(int u, int p) {
num[u] = low[u] = ++timeDfs;
for (auto [v, i, t] : g[u]) if(v != p) {
if (vs[v]) continue;
if (!num[v]){
dfs(v, u);
if(low[v] == num[v]) bridge[i] = 1;
low[u] = min(low[u], low[v]);
}
else low[u] = min(low[u], num[v]);
}
}
void cay(int u, int sc) {
id[u] = sc;
// cout << u << ' ' << id[u] << ' ' << low[u] << ' ' << num[u] << '\n';
for(auto [v, i, t] : g[u]) {
if(id[v] || bridge[i]) continue;
cay(v, sc);
}
}
int val[ar];
int cnt[ar];
void dfs3(int u, int p) {
vs[u] = 1;
for(auto &[v, i, t] : adj[u]) {
if(v == p) continue;
dfs3(v, u);
if(cnt[v] < 0) val[i] = t ^ 1;
else if(cnt[v] > 0) val[i] = t;
cnt[u] += cnt[v];
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
#define task "CEOI17_ONEWAY"
if(fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
cin >> n >> m;
int u, v;
memset(val, -1, sizeof val);
for(int i = 1; i <= m; ++i) {
cin >> u >> v;
g[u].push_back({v, i, 0});
g[v].push_back({u, i, 1});
}
int dem = 0;
for(int i = 1; i <= n; ++i) if(num[i] == 0)
dfs(i, 0);
for(int i = 1; i <= n; ++i) if(id[i] == 0) {
scc++;
cay(i, scc);
}
for(int u = 1; u <= n; ++u)
for(auto [v, i, t] : g[u]) if(id[u] != id[v])
adj[id[u]].push_back({id[v], i, t});
int q;
cin >> q;
while(q--) {
cin >> u >> v;
u = id[u]; v = id[v];
cnt[u]++;
cnt[v]--;
}
memset(vs, 0, sizeof vs);
for(int i = 1; i <= scc; ++i) if(!vs[i])
dfs3(i, 0);
for(int i = 1; i <= m; ++i) {
if(val[i] == -1) cout << 'B';
else if(val[i] == 0) cout << 'L';
else cout << 'R';
}
}
