#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
#define X first
#define Y second
const int MXN = 1e5+5, LOG = 17;
int n, m, p, U[MXN], V[MXN], h[MXN], mn[MXN], dsu[MXN];
vector<int> g[MXN];
int find(int v) { return v==dsu[v] ? v : dsu[v]=find(dsu[v]); }
vector<int> bridges;
void dfs1(int v, int pid=-1) {
if(pid!=-1) mn[v] = h[v] = h[v^U[pid]^V[pid]]+1;
else mn[v] = h[v] = 1;
for(int i : g[v]) {
int u = v^U[i]^V[i];
if(!h[u]) {
dfs1(u, i);
mn[v] = min(mn[v], mn[u]);
}
else if(i!=pid) mn[v] = min(mn[v], h[u]);
}
if(mn[v]==h[v]) {
dsu[v] = v;
if(pid!=-1) bridges.push_back(pid);
}
else dsu[v] = v^U[pid]^V[pid];
}
vector<pii> G[MXN];
inline void build() {
for(int v=1; v<=n; v++)
if(!h[v])
dfs1(v);
for(int i : bridges)
G[find(U[i])].push_back({find(V[i]), i}),
G[find(V[i])].push_back({find(U[i]), i});
}
bool vis[MXN];
int par[MXN][LOG];
void dfs2(int v) {
h[v] = h[par[v][0]]+1;
for(int i=1; i<LOG; i++)
par[v][i] = par[par[v][i-1]][i-1];
for(auto [u, i] : G[v])
if(u!=par[v][0]) {
par[u][0] = v;
dfs2(u);
}
}
inline int jump(int v, int d) {
for(int i=0; i<LOG; i++)
if(d>>i&1)
v = par[v][i];
return v;
}
inline int LCA(int u, int v) {
if(h[u]<h[v]) swap(u, v);
u = jump(u, h[u]-h[v]);
if(u==v) return u;
for(int i=LOG-1; i>=0; i--)
if(par[u][i]!=par[v][i])
u = par[u][i], v = par[v][i];
return par[u][0];
}
int up[MXN], down[MXN];
string ans;
inline void add(int u, int v) {
if((u=find(u))==(v=find(v))) return;
int lca = LCA(u, v);
up[u]++;
up[lca]--;
down[v]++;
down[lca]--;
}
void dfs3(int v, int pid=-1) {
vis[v] = 1;
for(auto [u, i] : G[v])
if(i!=pid)
dfs3(u, i),
up[v] += up[u],
down[v] += down[u];
if(up[v])
ans[pid] = find(U[pid])==v ? 'R' : 'L';
else if(down[v])
ans[pid] = find(U[pid])==v ? 'L' : 'R';
}
int32_t main() {
cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
cin >> n >> m;
for(int i=0; i<m; i++) {
cin >> U[i] >> V[i];
g[U[i]].push_back(i);
g[V[i]].push_back(i);
}
build();
fill(h+1, h+n+1, 0);
for(int v=1; v<=n; v++)
if(!h[find(v)])
dfs2(find(v));
cin >> p;
for(int i=0,u,v; i<p; i++) {
cin >> u >> v;
add(u, v);
}
ans = string(m, 'B');
for(int v=1; v<=n; v++)
if(!vis[find(v)])
dfs3(find(v));
cout << ans << '\n';
return 0;
}
