/* KHODA HAST */
#include <bits/stdc++.h>
using namespace std;
typedef long long ll ;
typedef pair<ll , ll > pii ;
const ll mod = 1e9 +7;
const ll inf = 8e18;
const int N = 3e5+12 ;
#define s second
#define f first
#define pb push_back
#define ms(x , y) memset(x , y , sizeof x)
#define ret(x) cout << x << endl ,exit(0) ;
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}
vector <pii> adj[N] , adj2[N] ;
vector <int> vh[N] ;
bool bor[N] , sn[N] ;
int mol[N] , r[N] , l[N] , t = 0 , h[N] , tim = 0 , st[N] , ps[2][N] , y[2][N] , ps1[N] , thes[N];
int n , m ;
void dfs(int v , int p, int y ){
sn[v] = 1 ;
for(pii u : adj[v]){
if(!sn[u.f]){
h[u.f] = h[v]+1 ;
dfs(u.f , v , u.s) ;
ps1[v]+=ps1[u.f] ;
}
if(sn[u.f] && u.f != p && h[u.f] < h[v] ){
ps1[u.f]-- ; ps1[v]++ ;
}
}
if(ps1[v] == 0 && p!=0 ){
bor[y] = 1 ;
}
}
void dfs2(int v){
sn[v] = 1 ; mol[v] = t ;
for(pii u : adj[v]){
if(!sn[u.f] && !bor[u.s])dfs2(u.f);
}
}
void dfs3(int v) {
sn[v] = 1 ;
for(pii u : adj[v]){
if(!sn[u.f]) {
if(bor[u.s]){
adj2[mol[u.f]].pb({mol[v] , u.s}) ;
adj2[mol[v]].pb({mol[u.f] , u.s}) ;
}
dfs3(u.f) ;
}
}
}
void dfs4(int v){
sn[v] = 1 ;
thes[tim] = v ;
vh[h[v]].pb(tim) ;
tim++;
for(pii u : adj2[v]){
if(!sn[u.f]){
h[u.f] = h[v]+1 ;
dfs4(u.f) ;
}
}
tim++;
return ;
}
void dfs5(int v ){
sn[v] = 1 ;
for(pii u : adj2[v]){
if(!sn[u.f]){
ps[0][u.f] += ps[0][v] ;
dfs5(u.f) ;
ps[1][v] += ps[1][u.f] ;
y[1][u.s] = u.f ; y[0][u.s] = v ;
}
}
return ;
}
int the_jad(int v , int k ){
if(vh[h[v] - k ].size() == 0 || h[v] < k )return -1 ;
auto u = upper_bound(vh[h[v] - k ].begin() , vh[h[v] - k ].end() , st[v]) - vh[h[v] - k].begin();
u = vh[h[v] - k ][u] ;
return thes[u] ;
}
int lca(int x , int y){
int l = 0 , r = n+1 , md ;
while(r - l > 1){
md = (l+r)/2 ;
if(the_jad(x , md) == the_jad(y , md) || the_jad(x , md) == -1 || the_jad(y , md) == -1 ){
r = md ;
}
else l = md ;
}
return the_jad(x , r) ;
}
void solve(){
cin >> n >> m ;
fill(sn , sn+n+ 1 , 0 ) ;
for(int i = 0 ; i <= n ; i++){
st[i] = 0 ;
thes[i] = 0 ;
}
for(int i = 1 ; i <= m ; i++){
int v , u ;
cin >> v >> u ; adj[u].pb({v , i}); adj[v].pb({u , i});
r[m] = u , l[m] = v;
}
h[1] = 0 ;
dfs(1 , 0 , 0 ) ;
fill(sn , sn+n+ 1 , 0 ) ;
for(int i = 1 ; i <= n ; i++)
if(!sn[i]){t++; dfs2(i) ; }
fill(sn , sn+n+ 1 , 0 ) ;
dfs3(1) ;
fill(sn , sn+n+1 , 0) ;
fill(h , h+n+1 , 0 ) ;
dfs4(1) ;
int p ;
cin >> p ;
while(p--){
int x , y ;
cin >> x >> y ;
x = mol[x] ; y = mol[y] ;
if(x == y)continue ;
int p = lca(x , y ) ;
ps[1][x]++ ; ps[1][p]--;
ps[0][y]--; ps[0][p]++;
}
fill(sn , sn+n+1 , 0) ;
dfs5(1) ;
string ans = "" ;
for(int i = 1 ; i <= m ; i++){
int up = y[1][i] , dw = y[0][i] ;
if(bor[i] == 1 ) {
if(ps[1][up] > 0 ){
if(r[i] == up )ans+='L' ;
else ans+='R' ;
}
else if(ps[0][dw] > 0){
if(r[i] == dw )ans+='L' ;
else ans+='R' ;
}
}
else ans+='B' ;
}
cout << ans << endl;
}
int main(){
cin.tie(0)->sync_with_stdio(0) ;
solve() ;
return 0 ;
}
