#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define _ <<' '<<
#define print(x) cout<<#x<<": "<<(x)<<'\n'
int n,m,q,c=-1,k,d=-1;
vector<vector<array<int, 2>>> adj, aj2;
vector<array<int, 2>> eg;
vector<int> num, low, bg, cmp, up, dp, par, vis, in, out, res;
vector<vector<int>> st;
void dfs(const int u, const int p) {
num[u]=low[u]=++c;
bool flag=true;
for (const auto [v, i]:adj[u]) {
if (v==p && flag) {
flag=false;
continue;
}
if (num[v]==-1) {
dfs(v, u);
low[u]=min(low[u], low[v]);
if (low[v]>num[u]) bg[i]=1;
}
low[u]=min(low[u], num[v]);
}
}
void tj(){
for (int i=0; i<n; i++) if (num[i]==-1) dfs(i, i);
}
void dfs2(const int u) {
cmp[u]=c;
for (const auto [v, i]:adj[u]) if (!bg[i] && cmp[v]==-1) {
dfs2(v);
}
}
void dfs3(const int u) {
vis[u]=1;
in[u]=++d;
for (const auto [v, i]:aj2[u]) if (!vis[v]) {
par[v]=u;
dfs3(v);
}
out[u]=d;
}
bool anc(const int a, const int b) {
return in[a]<=in[b] && out[b]<=out[a];
}
int lca(const int a, const int b) {
if (anc(a, b)) return a;
if (anc(b, a)) return b;
int x=a;
for (int i=k-1; i>=0; --i) if (!anc(st[i][x], b)) x=st[i][x];
return st[0][x];
}
void dfs4(const int u) {
vis[u]=1;
for (const auto [v, i]:aj2[u]) if (v!=par[u]) {
dfs4(v);
if (dp[v]) {
if (cmp[eg[i][0]]==u) res[i]=1;
else res[i]=-1;
} else if (up[v]) {
if (cmp[eg[i][1]]==u) res[i]=1;
else res[i]=-1;
}
dp[u]+=dp[v];
up[u]+=up[v];
}
assert((!up[u]) || (!dp[u]));
}
int main(){
cin.tie(0)->sync_with_stdio(0);
cout.tie(0);
cin>>n>>m;
adj.resize(n);
eg.resize(m);
num.assign(n, -1);
low.assign(n, -1);
bg.assign(m, 0);
cmp.assign(n, -1);
res.assign(m, 0);
for (int i=0; i<m; i++) {
int a,b;
cin>>a>>b;
adj[--a].push_back({--b, i});
adj[b].push_back({a, i});
eg[i]={a, b};
}
//cout<<'a'<<endl;
tj();
//cout<<'b'<<endl;
c=0;
for (int i=0; i<n; i++) if (cmp[i]==-1) {
dfs2(i);
++c;
}
//cout<<'c'<<endl;
aj2.resize(c);
par.assign(c, 0);
in.assign(c, -1);
out.assign(c, -1);
vis.assign(c, 0);
for (int i=0; i<m; i++) if (bg[i]) {
aj2[cmp[eg[i][0]]].push_back({cmp[eg[i][1]], i});
aj2[cmp[eg[i][1]]].push_back({cmp[eg[i][0]], i});
}
//cout<<'d'<<endl;
for (int i=0; i<c; i++) if (!vis[i]) {
par[i]=i;
dfs3(i);
}
up.assign(c, 0);
dp=up;
k=max(1, 32-__builtin_clz(c));
//cout<<'e'<<endl;
cin>>q;
st.assign(k, vector<int>(c, 0));
st[0]=par;
for (int i=1; i<k; i++) for (int j=0; j<c; j++) {
st[i][j]=st[i-1][st[i-1][j]];
}
for (int i=0; i<q; i++) {
int a,b;
cin>>a>>b;
a=cmp[--a];
b=cmp[--b];
const auto l=lca(a, b);
++up[a];
--up[l];
--dp[l];
++dp[b];
}
vis.assign(c, 0);
for (int i=0; i<c; i++) if (!vis[i]) dfs4(i);
for (const auto e:res) {
if (e==-1) cout<<'L';
else if (!e) cout<<'B';
else cout<<'R';
}
cout<<'\n';
}
