#include <bits/stdc++.h>
#define dbg(x) "[" #x " = " << x << "]"
#define BIT(x, i) (((x) >> (i)) & 1)
using namespace std;
const int MAXN = 1e5 + 5, LOG = 20;
template<class X, class Y>
bool minimize(X &x, const Y &y){
if (x > y){
x = y; return 1;
}
return 0;
}
struct edge{
int u, v;
edge(int _u = 0, int _v = 0): u(_u), v(_v) {};
int other(int &x){
return u ^ v ^ x;
}
bool isLeft(int x){
return u == x;
}
};
int numNode, numEdge, numQuery, low[MAXN], num[MAXN], mark[MAXN], down[MAXN], go[MAXN], up[MAXN][LOG], h[MAXN], res[MAXN];
bool visited[MAXN];
vector<int> adj[MAXN], nadj[MAXN], can;
stack<int> st;
edge e[MAXN];
void tarjan(int u, int par = 0){
low[u] = num[u] = ++num[0];
st.push(u);
for(int id: adj[u]) if (id != par){
int v = e[id].other(u);
if (!num[v]){
tarjan(v, id);
minimize(low[u], low[v]);
if (low[v] == num[v]) can.push_back(id);
}else minimize(low[u], num[v]);
}
if (low[u] != num[u]) return;
int v;
do{
v = st.top(); st.pop(); mark[v] = u;
}while(v != u);
}
void dfsInit(int u, int par = 0){
visited[u] = 1;
for(int id: nadj[u]) if (id != par){
int v = e[id].other(u);
h[v] = h[u] + 1;
up[v][0] = u;
for(int i = 1; i < LOG; i++)
up[v][i] = up[up[v][i - 1]][i - 1];
dfsInit(v, id);
}
}
int lca(int u, int v){
if (h[u] < h[v]) swap(u, v);
int k = h[u] - h[v];
for(int i = LOG - 1; i >= 0; i--) if (BIT(k, i)) u = up[u][i];
if (u == v) return u;
for(int i = LOG - 1; i >= 0; i--) if (up[u][i] != up[v][i])
u = up[u][i], v = up[v][i];
return up[u][0];
}
int tmp;
void dfs(int u, int par = 0){
visited[u] = 1;
for(int id: nadj[u]) if (id != par){
int v = e[id].other(u);
dfs(v, id);
down[u] += down[v]; go[u] += go[v];
if (go[v] > 0) res[id] = (e[id].isLeft(u) ? 2: 1);
if (down[v] > 0) res[id] = (e[id].isLeft(u) ? 1: 2);
}
}
void input(){
cin >> numNode >> numEdge;
for(int i = 1; i <= numEdge; i++){
cin >> e[i].u >> e[i].v;
adj[e[i].u].push_back(i);
adj[e[i].v].push_back(i);
}
}
void solve(){
tarjan(1);
int u, v;
for(int i = 1; i <= numNode; i++) if (!num[i]) tarjan(i);
for(int x: can){
u = mark[e[x].u], v = mark[e[x].v];
e[x].u = u; e[x].v = v;
nadj[u].push_back(x);
nadj[v].push_back(x);
}
for(int i = 1; i <= numNode; i++) if (!visited[i]) dfsInit(i);
cin >> numQuery;
while(numQuery--){
cin >> u >> v;
u = mark[u], v = mark[v];
int p = lca(u, v);
go[u]++; go[p]--;
down[v]++; down[p]--;
}
memset(visited, 0, sizeof visited);
for(int i = 1; i <= numNode; i++) if (!visited[i]) dfs(i);
// for(int i = 1; i <= numNode; i++) cout << dp[i] << ' '; cout << '\n';
// for(int i = 1; i <= numNode; i++) cout << res[i] << ' '; cout << '\n';
// cout << root << ": \n";
// for(int i = 1; i <= numEdge; i++) cout << res[i] << ' '; cout << '\n';
// for(int i = 1; i <= numEdge; i++) cout << res[i] << ' '; cout << '\n';
for(int i = 1; i <= numEdge; i++) cout << (res[i] == 0 ? 'B': (res[i] == 1 ? 'R': 'L'));
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
input();
solve();
}
