#include <bits/stdc++.h>
using namespace std;
#define all(v) v.begin(), v.end()
typedef long long ll;
const int NMAX = 1e5 + 5;
int n, m, P, a[NMAX], b[NMAX], u, v, vis[NMAX];
int dfsn[NMAX], low[NMAX], t, cl[NMAX], ans[NMAX], chk[NMAX], f[NMAX];
vector<pair<int, int>> adj[NMAX], g[NMAX];
void dfs(int x, int e){
dfsn[x] = low[x] = ++t;
for(auto& [nx, ix] : adj[x]){
if(ix == e) continue;
if(!dfsn[nx]){
dfs(nx, ix);
low[x] = min(low[x], low[nx]);
}
else if(dfsn[nx] < dfsn[x]) low[x] = min(low[x], dfsn[nx]);
}
return;
}
void dfs2(int x, int c){
cl[x] = c;
for(auto& [nx, ix] : adj[x]){
if(cl[nx]) continue;
if(low[nx] > dfsn[x]) {
g[c].emplace_back(++t, ix);
g[t].emplace_back(c, ix);
dfs2(nx, t);
}
else dfs2(nx, c);
}
return;
}
void dfs3(int x){
vis[x] = 1;
for(auto& [nx, ix] : g[x]){
if(vis[nx]) continue;
dfs3(nx);
if(chk[nx]){
if(chk[nx] > 0 && nx == cl[a[ix]] || chk[nx] < 0 && x == cl[a[ix]]) ans[ix] = 1;
else ans[ix] = -1;
}
chk[x] += chk[nx];
}
return;
}
int main(void){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m;
for(int i = 0; i < m; i++){
cin >> a[i] >> b[i];
f[i] = 1;
adj[a[i]].emplace_back(b[i], i);
adj[b[i]].emplace_back(a[i], i);
}
for(int i = 1; i <= n; i++)
if(!dfsn[i]) dfs(i, -1);
t = 0;
for(int i = 1; i <= n; i++)
if(!cl[i]) dfs2(i, ++t);
cin >> P;
while(P--){
cin >> u >> v;
chk[cl[u]]++; chk[cl[v]]--;
}
for(int i = 1; i <= t; i++)
if(!vis[i]) dfs3(i);
for(int i = 0; i < m; i++){
if(!ans[i]) cout << 'B';
else cout << (ans[i] > 0 ? 'R' : 'L');
}
return 0;
}
