#include <iostream>
#include <vector>
using namespace std;
const int N = 1<<17;
vector<pair<int,int>> nei[N];
int hei[N], par[N][20], seen[N], cyc[N], Down[N], Up[N], Ans[N];
void dfs(int u, int p){
hei[u] = hei[p] + 1, seen[u] = 1, par[u][0] = p;
for (int i=1;i<17;i++)
par[u][i] = par[par[u][i-1]][i-1];
for (auto [i, id] : nei[u]){
if (seen[i] == 1)
continue;
dfs(i, u);
}
}
void dfs2(int u, int ind){
seen[u] = 2;
for (auto [i, id] : nei[u]){
if (id == -ind)
continue;
if (seen[i] == 2){
Ans[abs(id)] = 'B';
cyc[u]++;
cyc[i]--;
}
else{
dfs2(i, id);
Up[u] += Up[i];
Down[u] += Down[i];
cyc[u] += cyc[i];
}
}
if (cyc[u] or Up[u] + Down[u] == 0)
Ans[abs(ind)] = 'B';
else if ((Up[u] > 0) == (ind < 0))
Ans[abs(ind)] = 'R';
else
Ans[abs(ind)] = 'L';
}
int Lca(int u, int v){
if (hei[u] > hei[v])
swap(u, v);
for (int i=16;i>=0;i--)
if (hei[u] + (1<<i) <= hei[v])
v = par[v][i];
for (int i=16;i>=0;i--)
if (par[u][i] != par[v][i])
u = par[u][i], v = par[v][i];
return (u == v ? u : par[u][0]);
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
int n, m, q;
cin>>n>>m;
for (int i=1, a, b;i<=m;i++){
cin>>a>>b;
nei[a].push_back({b, i});
nei[b].push_back({a, -i});
}
dfs(1, 0);
cin>>q;
for (int i=1, A, B;i<=q;i++){
cin>>A>>B;
int lca = Lca(A, B);
Up[A]++, Down[B]++, Up[lca]--, Down[lca]--;
}
dfs2(1, 0);
for (int i=1;i<=m;i++)
cout<<char(Ans[i]);
cout<<'\n';
}
