#pragma GCC diagnostic warning "-std=c++11"
#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define f first
#define s second
#define MOD 1000000007
#define flush fflush(stdout)
#define all(x) (x).begin(),(x).end()
#define allr(x) (x).rbegin(), (x).rend()
#define pii pair<int,int>
using namespace std;
const int N=1e5+5;
int n,m,T,k,q,fix[N],depth[N],anc[N][20],d[N],val[N],big=1e9,dp[N];
map<pii,int> mymap,mymap2;
vector<int> g[N];
vector<pair<int,pii>> e[N];
vector<pii> br;
map<pii,pii> ne;
void dfs(int x, int p) {
fix[x]=1;
depth[x]=depth[p]+1;
int up=0,down=0;
for (auto y:g[x]) {
if (fix[y]) {
if (depth[x]>depth[y]) up++;
else down++;
continue;
}
dfs(y,x); dp[x]+=dp[y];
}
if (x==1) up++;
dp[x]+=(up-1)-down;
// cout<<"XP "<<x<<" "<<p<<" "<<dp[x]<<endl;
if (x!=1 && dp[x]==0) {
br.pb({x,p});
mymap2[{x,p}]=mymap2[{p,x}]=1;
}
}
int p[N],sz[N];
void make_set(int v) {
sz[v]=1; p[v]=v;
}
int find_set(int v) {
if (p[v]==v) return v;
return p[v]=find_set(p[v]);
}
void merge_set(int a, int b) {
a=find_set(a); b=find_set(b);
if (a==b) return;
if (sz[a]<sz[b]) swap(a,b);
p[b]=a; sz[a]+=sz[b];
}
int ancestor(int a, int b) {
int res=a;
for (int j=0; j<20; j++) {
if (b&(1<<j)) res=anc[res][j];
}
return res;
}
int LCA(int a, int b) {
if (d[a]>d[b]) {
a=ancestor(a,d[a]-d[b]);
}
else if (d[b]>d[a]) {
b=ancestor(b,d[b]-d[a]);
}
if (a==b) return a;
for (int j=19; j>=0; j--) {
if (anc[a][j]!=anc[b][j]) {
a=anc[a][j]; b=anc[b][j];
}
}
return anc[a][0];
}
void dfs0(int x, int p) {
anc[x][0]=p; d[x]=d[p]+1;
for (auto A:e[x]) {
int y=A.f;
if (y==p) continue;
dfs0(y,x);
}
}
string s;
void solve(int x, int p) {
for (auto A:e[x]) {
int y=A.f;
if (y==p) continue;
solve(y,x); val[x]+=val[y];
}
if (p==0) return;
if (val[x]==0) return;
int xx=ne[{x,p}].f,yy=ne[{x,p}].s;
x=xx,p=yy;
if (val[x]<big) {
if (mymap[{x,p}]) {
s[mymap[{x,p}]-1]='R';
}
else {
s[mymap[{p,x}]-1]='L';
}
}
else {
if (mymap[{x,p}]) {
s[mymap[{x,p}]-1]='L';
}
else {
s[mymap[{p,x}]-1]='R';
}
}
}
void test_case() {
cin>>n>>m;
for (int i=1; i<=m; i++) {
int a,b; cin>>a>>b;
g[a].pb(b); g[b].pb(a);
mymap[{a,b}]=i;
s.pb('B');
}
dfs(1,0);
for (int i=1; i<=n; i++) make_set(i);
for (int i=1; i<=n; i++) {
for (auto j:g[i]) {
if (mymap2[{i,j}]) continue;
merge_set(i,j);
}
}
int root=find_set(1);
for (auto A:br) {
int x=A.f,y=A.s;
int xx=x; int yy=y;
x=find_set(x); y=find_set(y);
// cout<<x<<" "<<y<<endl;
ne[{x,y}]={xx,yy};
ne[{y,x}]={yy,xx};
e[x].pb({y,{xx,yy}}); e[y].pb({x,{yy,xx}});
}
dfs0(root,0);
for (int j=1; j<20; j++) {
for (int i=1; i<=n; i++) {
anc[i][j]=anc[anc[i][j-1]][j-1];
}
}
cin>>q;
while (q--) {
int a,b; cin>>a>>b;
a=find_set(a); b=find_set(b);
int c=LCA(a,b);
// cout<<a<<" "<<b<<" "<<c<<endl;
val[a]+=1; val[c]-=1; val[b]+=big; val[c]-=big;
}
solve(root,0);
cout<<s<<endl;
}
main () {
ios :: sync_with_stdio(0);
cin.tie(0); cout.tie(0);
T=1;
while (T--) test_case();
}
