#include <bits/stdc++.h>
#include <fstream>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define mod 1000000007
#define INF 1000000000
#define INF2 2000000000
#define fi first
#define se second
using namespace std;
double const EPS = 1e-14;
const int P = 1007;
typedef long long ll;
using namespace __gnu_pbds;
typedef long long ll;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; // find_by_order, order_of_key
const int Max = 1e5 + 5;
vector<int> v[Max];
int sta[Max], low[Max], par[Max];
int tim = 0, cntx = 0, cnty = 0;
map<pair<int,int>,int> mp, check;
bool vis[Max], ok = false;
int okx[Max], oky[Max];
void dfs(int s, int p) {
tim++;
vis[s] = 1; sta[s] = tim; low[s] = tim;
for(auto i : v[s]) {
if(vis[i] == 0) {
dfs(i,s);
low[s] = min(low[s],low[i]);
okx[s]+=okx[i];
oky[s]+=oky[i];
if(low[i] > sta[s]) {
if(okx[i] > oky[i]) {
mp[{i,s}] = 2;
mp[{s,i}] = 3;
}
else if(okx[i] < oky[i]) {
mp[{s,i}] = 2;
mp[{i,s}] = 3;
}
}
}
else if(i != p || par[s] > 0){
low[s] = min(sta[i],low[s]);
}
else if(i == p) {
par[s]++;
}
}
}
int main()
{
ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
int n, m; cin >> n >> m;
pair<int,int> edge[m];
for(int i = 0; i < m; i++) {
int a, b; cin >> a >> b;
edge[i].fi = a, edge[i].se = b;
v[a].push_back(b);
v[b].push_back(a);
}
int p; cin >> p;
while(p--) {
int a, b; cin >> a >> b;
okx[a]++; oky[b]++;
}
for(int i = 1; i <= n; i++) {
if(vis[i] == 0) {
cntx = 0; cnty = 0; dfs(i,0);
}
}
for(int i = 0; i < m; i++) {
if(mp[{edge[i].fi,edge[i].se}] == 0) cout << 'B';
else if(mp[{edge[i].fi,edge[i].se}] == 3) cout << 'L';
else cout << 'R';
}
cout << endl;
return 0;
}
