#include <iostream>
#include<bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define pb push_back
#define x first
#define y second
#define lb lower_bound
#define mp make_pair
int n, m, p, com[100005], pre[100005], num[100005], c, a, b;
int par[20][100005], d[100005], one[100005], dir[100005];
vector<pii> st[100005];
vector<pii> v[100005], w[100005];
vector<int> vis;
void dfs(int N, int P){
if (num[N]!=0) return;
num[N]=(pre[N]=++c);
//if (num[N]==1) exit(2);
vis.pb(N);
for (int l=0; l<v[N].size(); ++l){
if (v[N][l].x==P) {P=-1; continue;}
dfs(v[N][l].x, N);
pre[N]=min(pre[N], pre[v[N][l].x]);
}
if (pre[N]==num[N]){
int t=-1;
do{
t=vis.back(); vis.pop_back();
com[t]=N;
//cout << N << ' ' << t << endl;
for (int l=0; l<v[t].size(); ++l){
w[N].pb(v[t][l]);
}
} while(t!=N);
}
}
void dfs2(int N, int P){
N=com[N];
if (P==-1) d[N]=1; else d[N]=d[P]+1;
for (int l=0; l<20; ++l) par[l][N]=-1;
par[0][N]=P;
int k=0;
while(par[k][N]!=-1){
par[k+1][N]=par[k][par[k][N]]; ++k;
}
for (int l=0; l<w[N].size(); ++l){
w[N][l].x=com[w[N][l].x];
if (w[N][l].x==N || w[N][l].x==P) continue;
dfs2(w[N][l].x, N);
}
}
void lca(int a, int b){
int A=(a=com[a]), B=(b=com[b]), k=19;
if (a==b) return;
while(d[A]>d[B]){
//cout << A << ' ' << d[A] << endl;
while(k>0 && (d[A]-(1 << k)<d[B])) k--;
A=par[k][A];
}
while(d[B]>d[A]){
//cout << B << ' ' << d[B] << endl;
while(k>0 && (d[B]-(1 << k)<d[A])) k--;
B=par[k][B];
}
k=19;
while(A!=B){
while(k>0 && par[k][A]==par[k][B]){
--k;
}
A=par[k][A]; B=par[k][B];
//cout << k << ' ' << A << ' ' << B << endl;
}
//cout << A << ' ' <<B << endl;return;
st[a].pb(mp(A, 1));
st[b].pb(mp(A, 0));
//cout << a << ' ' << A << ' ' << b << endl;
}
multiset<int> s[2];
void dfs3(int N, int P){
N=com[N]; com[N]=0;
for (int l=0; l<st[N].size(); ++l){
s[st[N][l].y].insert(st[N][l].x);
}
//cout << N << ' ' << s[0].size()<< ' ' << s[1].size() << endl;
int a, b, t;
for (int l=0; l<w[N].size(); ++l){
if (w[N][l].x==N || w[N][l].x==P) continue;
a=s[0].size(); b=s[1].size();
dfs3(w[N][l].x, N);
t=0;
//if (s[0].size()>a && s[1].size()>b) exit(1);
if (s[0].size()>a) t=1;
if (s[1].size()>b) t=2;
if (w[N][l].y<0){
t=(3-t)%3; w[N][l].y*=-1;
}
//cout << N << ' ' << w[N][l].x << ' ' << P << ' ' << t << ' ' << w[N][l].y << endl;
dir[w[N][l].y]=t;
}
s[0].erase(N); s[1].erase(N);
}
int dist[100005][2], r[100005];
queue<pii> q;
bool dfs4(int N, int P, int D){
N=com[N]; num[N]=0;
if (N==D) return 1;
for (int l=0; l<w[N].size(); ++l){
w[N][l].x=com[w[N][l].x];
if (w[N][l].x==P || w[N][l].x==N) continue;
if (dfs4(w[N][l].x, N, D)){
//cout << N << ' ' << w[N][l].x << endl;
dir[abs(w[N][l].y)]=(w[N][l].y<0)+1;
//cout << "*" << endl;
return 1;
}
}
return 0;
}
void bfs(int A, int B){
dfs4(com[A], -1, com[B]);
}
int main() {
cin >> n >> m;
for (int l=0; l<m; ++l){
cin >> a >> b;
v[a].pb(mp(b, l+1)); v[b].pb(mp(a, -l-1));
}
for (int l=1; l<=n; ++l)
if (num[l]==0)
dfs(l, -1);
cin >> p;
if (p<=100 && 0){
for (int l=0; l<p; ++l){
cin >> a >> b;
bfs(a, b);
}
} else {
for (int l=1; l<=n; ++l)
if (par[0][com[l]]==0)
dfs2(com[l], -1);
for (int l=0; l<p; ++l){
cin >> a >> b;
lca(a, b);
}
for (int l=1; l<=n; ++l)
if (num[com[l]]!=0)
dfs3(com[l], -1);
}
for (int l=1; l<=m; ++l){
if (dir[l]==0) cout << "B";
else if (dir[l]==1) cout << "R";
else if (dir[l]==2) cout << "L";
else return 1;
}
return 0;
}
