#include <bits/stdc++.h>
using namespace std;
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#define flash ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define debug(x) cerr << " - " << #x << ": " << x << endl;
#define debugs(x, y) cerr << " - " << #x << ": " << x << " " << #y << ": " << y << endl;
#define all(x) (x).begin(),(x).end()
#define sz(x) (ll)x.size()
#define ll long long
#define INF 1000000000
#define MOD 1000000007
#define pb push_back
#define ve vector<ll>
#define dos pair<ll,ll>
#define vedos vector<dos>
#define rand mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define EPS 0.000001
struct greateri
{
template<class T>
bool operator()(T const &a, T const &b) const { return a > b; }
};
void setIO(string s) {
ios_base::sync_with_stdio(0); cin.tie(0);
freopen((s+".in").c_str(),"r",stdin);
freopen((s+".out").c_str(),"w",stdout);
}
ll tin[200001],tlow[200001],vis[200001],vis1[200001],dep[200001],pa[200001][30];
ve gr[200001],gr1[200001],tr[200001];
set<dos>brid;
ll n,m,p;
char ans[200001];
map<dos,ve>g;
ll timer,l;
ll col[200001];
void dfs(ll node,ll p){
vis[node]=1;
tin[node]=timer++;
tlow[node]=tin[node];
for(auto it:gr[node]){
if(it==p || it==node)continue;
if(vis[it]){
tlow[node]=min(tin[it],tlow[node]);
}
else{
dfs(it,node);
tlow[node]=min(tlow[node],tlow[it]);
if(tlow[it]>tin[node]){
brid.insert({min(node,it),max(node,it)});
}
}
}
}
void dfs1(ll node,ll co){
col[node]=co;
vis1[node]=1;
for(auto it:gr1[node]){
if(!vis1[it]){
dfs1(it,co);
}
}
}
void dfk(ll node,ll p,ll ka){
vis1[node]=1;
tin[node]=timer++;
dep[node]=ka;
pa[node][0]=p;
for (ll i = 1; i <= l; ++i)
{
pa[node][i]=pa[pa[node][i-1]][i-1];
}
for(auto it:tr[node]){
if(it!=p){
dfk(it,node,ka+1);
}
}
tlow[node]=timer++;
}
bool is_anc(ll u,ll v){
if(tin[u]<=tin[v] && tlow[u]>=tlow[v])return 1;
return 0;
}
ll lca(ll u,ll v){
if(is_anc(u,v))return u;
if(is_anc(v,u))return v;
for (ll i = l; i >= 0; --i)
{
if(!is_anc(pa[u][i],v)){
u=pa[u][i];
}
}
return pa[u][0];
}
ll parent[200000], depth[200000], heavy[200000], head[200000], pos[200000];
ll cur_pos;
ll lom(ll v) {
vis1[v]=1;
ll size = 1;
ll max_c_size = 0;
for (ll c : tr[v]) {
if (c != parent[v]) {
parent[c] = v, depth[c] = depth[v] + 1;
ll c_size = lom(c);
size += c_size;
if (c_size > max_c_size)
max_c_size = c_size, heavy[v] = c;
}
}
return size;
}
ll decompose(ll v, ll h) {
head[v] = h, pos[v] = cur_pos++;
if (heavy[v] != -1)
decompose(heavy[v], h);
for (ll c : tr[v]) {
if (c != parent[v] && c != heavy[v])
decompose(c, c);
}
}
ll bit[200001];
void add(ll idx, ll val) {
for (idx; idx <= n; idx += idx & -idx)
bit[idx] += val;
}
void range_add(ll l, ll r, ll val) {
add(l, val);
add(r + 1, -val);
}
ll point_query(ll idx) {
ll ret = 0;
for (idx; idx > 0; idx -= idx & -idx)
ret += bit[idx];
return ret;
}
void query(ll a, ll b,ll val) {
ll res = 0;
for (; head[a] != head[b]; b = parent[head[b]]) {
if (depth[head[a]] > depth[head[b]])
swap(a, b);
//debugs(pos[head[b]],pos[b])
//debug(val)
range_add(pos[head[b]]+1, pos[b]+1,val);
//debug(point_query(pos[head[b]]+1))
//res = max(res, cur_heavy_path_max);
}
if (depth[a] > depth[b])
swap(a, b);
//debugs(a,b)
//debug(val)
range_add(pos[a]+1, pos[b]+1,val);
return;
}
int main()
{
//flash;
cin>>n>>m;
l=log2(n);
vedos ed;
for (ll i = 0; i < m; ++i)
{
ll u,v;
cin>>u>>v;
u--,v--;
if(u==v){
ans[i]='B';
}
else{
ed.pb({u,v});
gr[u].pb(v),gr[v].pb(u);
if(u>v)swap(u,v);
g[{u,v}].pb(i);
}
}
for(auto it:g){
if(it.second.size()>1){
for(auto it1:it.second){
ans[it1]='B';
}
}
}
for (int i = 0; i < n; ++i)
{
if(!vis[i])dfs(i,-1);
}
set<dos>rem;
for(auto it:brid){
if(g[{it.first,it.second}].size()>1)rem.insert(it);
}
for(auto it:rem)brid.erase(it);
for(auto it:ed){
auto u=it.first,v=it.second;
if(u>v)swap(u,v);
if(brid.find({u,v})==brid.end()){
gr1[u].pb(v),gr1[v].pb(u);
}
}
ll ci=1;
for (ll i = 0; i < n; ++i)
{
if(!vis1[i]){
dfs1(i,ci);
ci++;
}
}
timer=0;
for(auto it:brid){
tr[col[it.first]].pb(col[it.second]);
tr[col[it.second]].pb(col[it.first]);
}
memset(vis1,0,sizeof vis1);
for (int i = 1; i < ci; ++i)
{
if(!vis1[i]){timer=0,dfk(i,i,0);}
}
ll q;
cin>>q;
memset(heavy,-1,sizeof heavy);
memset(vis1,0,sizeof vis1);
for (int i = 1; i < ci; ++i)
{
if(!vis1[i]){lom(i),decompose(i,i);}
}
while(q--){
ll u,v;
cin>>u>>v;
u--,v--;
if(col[u]==col[v])continue;
ll dol=lca(col[u],col[v]);
query(col[u],dol,1);
query(col[v],dol,-1);
}
for (ll i = 0; i < ed.size(); ++i)
{
auto u=ed[i].first,v=ed[i].second;
if(u>v)swap(u,v);
if(ans[i]!='B' && brid.find({u,v})!=brid.end() && col[u]!=col[v]){
if(dep[col[u]]<=dep[col[v]])swap(u,v);
ll cur=point_query(pos[col[u]]+1);
if(cur>0){
if(ed[i].first==u)ans[i]='R';
else ans[i]='L';
}
else if(cur<0){
if(ed[i].first==u)ans[i]='L';
else ans[i]='R';
}
else ans[i]='B';
}
else ans[i]='B';
}
for (ll i = 0; i < m; ++i)
{
cout<<ans[i];
}
return 0;
}
//code the AC sol !
// BS/queue/map
