#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> ii;
const int MAXN = 1e5 + 10;
const int BUCKET = 330;
vector<int> grafo[MAXN],tree[MAXN],procurar1[MAXN],procurar2[MAXN];
vector<ii> pares;
map<ii,int> cjt;
int low[MAXN],num[MAXN],jafoi[MAXN],dfsNum,compId[MAXN],compAtual;
int e1[MAXN],e2[MAXN],e3[MAXN],e4[MAXN],ehponte[MAXN];
int tipo1[MAXN],tipo2[MAXN],altura[MAXN],liga[MAXN],pai[MAXN],superpai[MAXN],q1[MAXN],q2[MAXN],N,M,K;
void dfs_tarjan(int v,int aresta){
num[v] = ++dfsNum;
low[v] = dfsNum;
for(int i : grafo[v]){
if(i == aresta) continue;
int u = (e1[i] != v) ? (e1[i]) : (e2[i]);
if(num[u] == 0){
dfs_tarjan(u,i);
if(low[u] > num[v]) ehponte[i] = 1;
low[v] = min(low[v],low[u]);
}
else{
low[v] = min(low[v],num[u]);
}
}
}
void dfs_bridge(int v,int aresta){
jafoi[v] = 1;
for(int i : grafo[v]){
if(i == aresta) continue;
int u = (e1[i] != v) ? (e1[i]) : (e2[i]);
if(jafoi[u]) continue;
if(ehponte[i]){
compAtual++;
compId[u] = compAtual;
dfs_bridge(u,i);
}
else{
compId[u] = compId[v];
dfs_bridge(u,i);
}
}
}
void dfs1(int v,int p){
//printf("DFS\n");
for(int i : tree[v]){
int u = (e3[i] != v) ? (e3[i]) : (e4[i]);
if(u == p) continue;
pai[u] = v;
liga[u] = i;
altura[u] = altura[v] + 1;
dfs1(u,v);
}
}
void dfs2(int v,int p,int sp){
superpai[v] = sp;
if((altura[v] - 1) % BUCKET == 0) sp = v;
for(int i : tree[v]){
int u = (e3[i] != v) ? (e3[i]) : (e4[i]);
if(u == p) continue;
dfs2(u,v,sp);
}
}
void LCA(int u,int v){
while(superpai[u] != superpai[v]){
if(altura[u] >= altura[v]){
q1[u]++;
u = superpai[u];
}
else{
q2[v]++;
v = superpai[v];
}
}
while(u != v){
//printf("U %d V %d\n",u,v);
if(altura[u] >= altura[v]){
//printf("Tipo1 %d %d\n",u,liga[u]);
tipo1[liga[u]]++;
u = pai[u];
}
else{
//printf("Tipo2 %d %d\n",v,liga[v]);
tipo2[liga[v]]++;
v = pai[v];
}
}
}
void processa(int v){
int d1 = q1[v],d2 = q2[v],alvo = superpai[v];
while(v != alvo){
tipo1[liga[v]] += d1;
tipo2[liga[v]] += d2;
v = pai[v];
}
}
int main(){
scanf("%d %d",&N,&M);
for(int i = 1;i<=M;i++){
scanf("%d %d",&e1[i],&e2[i]);
grafo[e1[i]].push_back(i);
grafo[e2[i]].push_back(i);
}
scanf("%d",&K);
for(int i = 1;i<=K;i++){
int u,v;
scanf("%d %d",&u,&v);
pares.push_back(ii(u,v));
}
for(int i = 1;i<=N;i++){
if(num[i] != 0) continue;
dfs_tarjan(i,-1);
compAtual++;
compId[i] = compAtual;
dfs_bridge(i,-1);
}
//printf("Pontes\n");
for(int i = 1;i<=M;i++){
if(!ehponte[i]) continue;
e3[i] = compId[e1[i]];
e4[i] = compId[e2[i]];
//printf("%d %d %d %d\n",e1[i],e2[i],e3[i],e4[i]);
tree[e3[i]].push_back(i);
tree[e4[i]].push_back(i);
}
for(int i = 1;i <= compAtual;i++){
if(altura[i] != 0) continue;
//printf("DFS1 %d\n",i);
altura[i] = 1;
dfs1(i,-1);
dfs2(i,-1,i);
//printf("Foi\n");
}
for(ii davez : pares){
int u = compId[davez.first],v = compId[davez.second];
if(u == v) continue;
LCA(u,v);
}
for(int i = 1;i<=compAtual;i++) processa(i);
for(int i = 1;i<=M;i++){
if(ehponte[i] == 0){
printf("B");
}
else if(tipo1[i]){
if(altura[e3[i]] > altura[e4[i]]) printf("R");
else printf("L");
}
else if(tipo2[i]){
if(altura[e3[i]] < altura[e4[i]]) printf("R");
else printf("L");
}
else{
printf("B");
}
}
printf("\n");
return 0;
}
