#include <bits/stdc++.h>
#define int long long
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
using namespace std;
int n,m,p;
vector<int> val;
vector<int> sm;
vector<int> depth;
vector<vector<int>> parent;
vector<vector<int>> sz;
vector<vector<int>> neigh;
int getParent(int x, int k){
if(parent[x][k]==x) return x;
return parent[x][k]=getParent(parent[x][k],k);
}
void unite(int a, int b, int k){
a=getParent(a,k);
b=getParent(b,k);
if(a==b) return;
if(sz[a][k]<sz[b][k]) swap(a,b);
sz[a][k]+=sz[b][k];
parent[b][k]=a;
}
int dfs(int x, int p, int d){
sm[x]=val[x];
depth[x]=d;
for (auto u : neigh[x])
{
if(u==p) continue;
sm[x]+=dfs(u,x,d+1);
}
return sm[x];
}
signed main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
cin >> n >> m;
vector<pair<int,int>> ed(m);
vector<vector<pair<pair<int,int>,int>>> tree_ed(2);
parent.resize(n,vector<int>(3,0));
sz.resize(n,vector<int>(3,1));
vector<char> ans(m,'B');
val.resize(n,0);
neigh.resize(n);
sm.resize(n,0);
depth.resize(n,0);
for (int i = 0; i < n; i++) parent[i][0]=parent[i][1]=parent[i][2]=i;
for (int i = 0; i < m; i++)
{
int a,b; cin >> a >> b; a--; b--;
ed[i]={a,b};
if(getParent(a,0)==getParent(b,0)) unite(a,b,1);
else unite(a,b,0);
}
for (int i = 0; i < m; i++)
{
int a=ed[i].first,b=ed[i].second;
if(getParent(a,1)!=getParent(b,1)) tree_ed[0].push_back({{getParent(a,1),getParent(b,1)},i});
}
int p; cin >> p;
for (int i = 0; i < p; i++)
{
int a,b; cin >> a >> b; a--; b--;
val[getParent(a,1)]++;
val[getParent(b,1)]--;
}
for (int i = 0; i < sz(tree_ed[0]); i++)
{
if(getParent(tree_ed[0][i].first.first,2)==getParent(tree_ed[0][i].first.second,2)) return -1;
neigh[tree_ed[0][i].first.first].push_back(tree_ed[0][i].first.second);
neigh[tree_ed[0][i].first.second].push_back(tree_ed[0][i].first.first);
unite(tree_ed[0][i].first.second, tree_ed[0][i].first.first,2);
}
dfs(0,0,0);
for (int i = 0; i < sz(tree_ed[0]); i++)
{
int a=tree_ed[0][i].first.first, b=tree_ed[0][i].first.second;
int s;
if(depth[a]<depth[b]) s=sm[b];
else s=sm[a];
if(s==0) continue;
if((s<0)^(depth[a]<depth[b])) ans[tree_ed[0][i].second]='L';
else ans[tree_ed[0][i].second]='R';
}
for (int i = 0; i < m; i++) cout << ans[i];
cout << "\n";
return 0;
}
