#include <iostream>
#include <vector>
#include <map>
using namespace std;
const int N=1e5+10,LG=18;
pair<int,int> edge[N];
int h[N],lw[N],par[N][LG],upe[N],up[N],su[N],eu[N],sd[N],ed[N],down[N];;
bool vis[N],bri[N];
vector<pair<int,int>> adj[N],ma[N];
void dfs(int x,int pid=0)
{
vis[x]=1;
for(int j=1;j<LG;j++)par[x][j]=par[par[x][j-1]][j-1];
lw[x]=h[x];
for(auto [y,id]:adj[x])
{
if(pid==id)continue;
if(!vis[y])
{
// cout<<"adding "<<x<<' '<<y<<endl;
ma[x].push_back({y,id});
h[y]=h[x]+1;
par[y][0]=x;
dfs(y,id);
if(lw[y]<h[y])
{
// cout<<"Non bridge "<<id<<endl;
bri[id]=0;
}
lw[x]=min(lw[x],lw[y]);
}
else{
// y is ancestor of x
// cout<<"Edge "<<id<<' '<<x<<' '<<y<<endl;
bri[id]=0;
lw[x]=min(lw[x],h[y]);
}
}
// cout<<"At "<<x<<' '<<h[x]<<' '<<lw[x]<<endl;
}
int lca(int x,int y)
{
if(h[x]<h[y])swap(x,y);
for(int j=LG-1;j>=0;j--)
{
if(h[par[x][j]]>=h[y])
{
x=par[x][j];
}
}
if(x==y)return y;
for(int j=LG-1;j>=0;j--)
{
if(par[x][j]!=par[y][j])
{
x=par[x][j];
y=par[y][j];
}
}
return par[x][0];
}
void dfs_(int x)
{
up[x]+=su[x];
down[x]+=sd[x];
for(auto [y,id]:ma[x])
{
dfs_(y);
up[y]-=eu[y];
down[y]-=ed[y];
if(up[y]>0)
{
upe[id]=y;
}
if(down[y]>0)
{
upe[id]=x;
}
up[x]+=up[y];
down[x]+=down[y];
}
// cout<<"Hello "<<x<<' '<<up[x]<<' '<<down[x]<<endl;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n,m;
cin>>n>>m;
for(int j=1;j<=m;j++)
{
int x,y;
cin>>x>>y;
edge[j]={x,y};
adj[x].push_back({y,j});
adj[y].push_back({x,j});
bri[j]=(x!=y);
upe[j]=-1;
}
// h[0]=0;
vector<int> rt;
for(int i=1;i<=n;i++)
{
if(!vis[i])h[i]=1,dfs(i),rt.push_back(i);
}
int p;
cin>>p;
for(int i=0;i<p;i++)
{
int x,y;
cin>>x>>y;
int l=lca(x,y);
su[x]++;
eu[l]++;
sd[y]++;
ed[l]++;
}
for(auto r:rt)
{
dfs_(r);
}
for(int j=1;j<=m;j++)
{
if(!bri[j] or upe[j]==-1)cout<<'B';
else if(edge[j].first==upe[j])cout<<'R';
else cout<<'L';
}
cout<<endl;
}
