#include<iostream>
#include<vector>
using namespace std;
const int INF = 1e9;
int n,m,p;
pair<int,int> e[100005];
int xr[100005];
vector<int> con[100005];
vector<int> relatii[100005];
bool visited[100005],visited_init[100005];
int mind[100005][3];///1 - in sus
int depth[100005];
int tin[100005],tout[100005],timer;
char rez[100005];
int anc[100005][17];
void dfs_init(int nod)
{
visited_init[nod]=1;
tin[nod]=++timer;
for(auto x:con[nod])
{
int adj = nod ^ xr[x];
if(!visited_init[adj])
{
anc[adj][0]=nod;
dfs_init(adj);
}
}
tout[nod]=++timer;
}
bool isanc(int x, int y)
{
if(tin[x]<=tin[y] && tout[x]>=tout[y])
return 1;
return 0;
}
void dfs(int nod, int par)
{
visited[nod]=1;
mind[nod][0]=mind[nod][1]=mind[nod][2]=INF;
for(auto x:con[nod])
{
if(x==par)
continue;
int adj = nod ^ xr[x];
if(!visited[adj])
{
depth[adj] = depth[nod]+1;
dfs(adj,x);
for(int i=0;i<3;i++) mind[nod][i] = min(mind[nod][i], mind[adj][i]);
}
else
{
rez[x] = 'B';
mind[nod][0] = min(mind[nod][0], depth[adj]);
}
}
for(auto x:relatii[nod])
{
if(x<0)
{
x = -x;
mind[nod][2] = min(mind[nod][2], depth[x]);
}
else
{
mind[nod][1] = min(mind[nod][1], depth[x]);
}
}
if(par==0)
return;
if(mind[nod][0] < depth[nod])
{
rez[par] = 'B';
}
else///bridge
{
if(mind[nod][1] >= depth[nod] && mind[nod][2] >= depth[nod])
rez[par] = 'B';
else
{
if(e[par].first==nod)
{
if(mind[nod][1] >= depth[nod]) rez[par] = 'R';
else rez[par] = 'L';
}
else
{
if(mind[nod][1] >= depth[nod]) rez[par] = 'L';
else rez[par] = 'R';
}
}
//rez[par]='X';
}
}
int lca(int x, int y)
{
if(isanc(x,y))
return x;
if(isanc(y,x))
return y;
for(int i=16;i>=0;i--)
if(!isanc(anc[x][i],y))
x = anc[x][i];
return anc[x][0];
}
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>m;
int a,b;
for(int i=1;i<=m;i++)
{
cin>>e[i].first>>e[i].second;
con[e[i].first].push_back(i);
con[e[i].second].push_back(i);
xr[i] = e[i].first ^ e[i].second;
}
for(int i=1;i<=n;i++)
{
if(!visited_init[i])
{
dfs_init(i);
anc[i][0]=1;
}
}
for(int k=1;k<17;k++)
for(int i=1;i<=n;i++)
anc[i][k] = anc[anc[i][k-1]][k-1];
cin>>p;
for(int i=1;i<=p;i++)
{
cin>>a>>b;
int lc = lca(a,b);
relatii[a].push_back(-lc);
relatii[b].push_back(lc);
}
for(int i=1;i<=n;i++)
if(!visited[i])
dfs(i,0);
for(int i=1;i<=m;i++)
cout<<rez[i];
return 0;
}
