#include <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <cstring>
#include <cmath>
#include <map>
#include <unordered_map>
#include <set>
#include <algorithm>
#include <iomanip>
#define F first
#define S second
#define PB push_back
#define PF push_front
#define MP make_pair
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int maxn = 1e5 + 10;
const int maxm = 1e5 + 10;
const int mod = 1e9 + 7;
bool visited[maxn], mark[maxn];
int dp[maxn], h[maxn], a[maxn], b[maxn], from[maxm];
vector <pii> g[maxn];
void dfs (int v, int par = -1, int idx = 0) {
mark[idx] = 1;
visited[v] = 1;
dp[v] = h[v];
for (auto u : g[v]) {
if (!mark[u.S] and u.F == par)
dp[v] = min (dp[v], h[v] - 1);
if (!visited[u.F]) {
h[u.F] = h[v] + 1;
dfs (u.F, v, u.S);
a[v] += a[u.F];
b[v] += b[u.F];
dp[v] = min (dp[v], dp[u.F]);
}
else if (u.F != par)
dp[v] = min (dp[v], h[u.F]);
}
// cout << v << " " << par << " -> " << dp[v] << " " << h[v] << endl;
if (par != -1 and dp[v] == h[v]) {
// cout << v << " = " << a[v] << " * " << b[v] << endl;
if (a[v] > b[v]) {
// cout << idx << " -> " << v << " " << par << endl;
from[idx] = v;
}
else if (a[v] < b[v]) {
// cout << idx << " -> " << par << " " << v << endl;
from[idx] = par;
}
}
}
pii edge[maxm];
int main() {
ios_base::sync_with_stdio(false);
int n, m;
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int v, u;
cin >> v >> u;
g[v].PB ({u, i});
g[u].PB ({v, i});
edge[i] = {v, u};
}
for (int i = 1; i <= n; i++)
random_shuffle (g[i].begin(), g[i].end());
int p;
cin >> p;
for (int i = 1; i <= p; i++) {
int x, y;
cin >> x >> y;
a[x] ++;
b[y] ++;
}
for (int i = 1; i <= n; i++) {
if (!visited[i]) {
dfs (i);
}
}
for (int i = 1; i <= m; i++) {
if (from[i] == edge[i].F)
cout << "R";
else if (from[i] == edge[i].S)
cout << "L";
else
cout << "B";
}
cout << endl;
}
