#include<bits/stdc++.h>
using namespace std;
int pre[100005];
int post[100005];
vector<int> graf[100005];
vector<int> graf_s[100005];
int dok[100005];
int odw[100005];
int low[100005];
int p = 1;
int po = 1;
int g= 1;
int jump[100005][20];
int wag[100005];
int wag1[100005];
int wyn[100005];
int gr[100005];
map<pair<int,int>,int> k1;
map<pair<int,int>,pair<int,int>> k;
set<pair<int,int>> pls;
void dfs(int x,int po)
{
//cout << x << endl;
odw[x] = 1;
pre[x] = p;
p++;
int malo = p-1;
for(int i : graf[x])
{
if(po == i) continue;
if(odw[i] == 0)
{
dok[i] = x;
dfs(i,x);
malo = min(low[i],malo);
}
else
{
malo = min(malo,pre[i]);
}
}
low[x] = malo;
}
void dfs1(int x)
{
odw[x] = 1;
pre[x] = p;
p++;
for(int i : graf_s[x])
{
if(odw[i] == 0)
{
jump[i][0] = x;
dfs1(i);
}
}
post[x] = po;
po++;
}
int lca(int x,int y)
{
if(pre[x] <= pre[y] && post[x] >= post[y])
{
return x;
}
if(pre[x] >= pre[y] && post[x] <= post[y])
{
return y;
}
for(int i = 18;i >= 0;--i)
{
if(jump[x][i] == 0) continue;
if(!(pre[jump[x][i]] <= pre[y] && post[jump[x][i]] >= post[y]))
{
x = jump[x][i];
}
}
return jump[x][0];
}
void dfs2(int x)
{
odw[x] = 1;
for(int i : graf_s[x])
{
if(odw[i] == 0)
{
dfs2(i);
wag[x] += wag[i];
}
}
}
void dfs3(int x)
{
odw[x] = 1;
for(int i : graf_s[x])
{
if(odw[i] == 0)
{
dfs3(i);
wag1[x] += wag1[i];
}
}
}
void dfs4(int x,int y)
{
odw[x] = 1;
gr[x] = y;
for(int i : graf[x])
{
if(odw[i] == 0 && low[i] != pre[i] && gr[i] == 0)
{
dfs4(i,y);
}
if(odw[i] == 0 && low[i] == pre[i])
{
g++;
dfs4(i,g);
}
}
}
int main()
{
ios_base::sync_with_stdio(0);
int n,m,a,b,m1;
cin >> n >> m;
m1 = m;
for(int i = 0;i < m;++i)
{
cin >> a >> b;
graf[a].push_back(b);
graf[b].push_back(a);
k1[{min(a,b),max(a,b)}] = i;
pls.insert({a,b});
}
for(int i = 1;i <= n;++i)
{
if(odw[i] == 0)
dfs(i,-1);
}
/*for(int i = 1;i <= n;++i)
{
//cout << pre[i] << ' ';
}
//cout << endl;
////cout << "2137 ";
for(int i = 1;i <= n;++i)
{
//cout << low[i] << ' ';
}
//cout << endl;*/
for(int i = 1;i <= n;++i)
{
odw[i] = 0;
}
for(int i = 1;i <= n;++i)
{
if(odw[i] == 0)
dfs4(i,g);
}
for(int i = 1;i <= n;++i)
{
//cout << gr[i] << ' ';
}
//cout << endl;
for(int i = 1;i <= n;++i)
{
odw[i] = 0;
}
for(int i = 2;i <= n;++i)
{
if(gr[i] != gr[dok[i]])
{
k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}] = {min(i,dok[i]),max(i,dok[i])};
graf_s[gr[i]].push_back(gr[dok[i]]);
graf_s[gr[dok[i]]].push_back(gr[i]);
}
}
for(int i = 1;i <= n;++i)
{
//cout << gr[i] << ':' << ' ';
for(int j : graf_s[gr[i]])
{
//cout << j << ' ';
}
//cout << endl;
}
for(int i = 1;i <= n;++i)
{
if(odw[i] == 0)
dfs1(i);
}
for(int i = 1;i <= 18;++i)
{
for(int j = 1;j <= n;++j)
{
jump[j][i] = jump[jump[j][i-1]][i-1];
}
}
p = 1;
for(int i = 1;i <= n;++i)
{
////cout << post[i] << ' ';
}
////cout << endl;
cin >> m;
for(int i = 1;i <= n;++i)
{
odw[i] = 0;
}
for(int i = 0;i < m;++i)
{
cin >> a >> b;
//cout << gr[a] << ' ' << gr[b] << ' ';
//cout<< gr[lca(gr[a],gr[b])] << endl;
wag[gr[a]]++;
wag1[gr[b]]++;
wag[gr[lca(gr[a],gr[b])]]--;
wag1[gr[lca(gr[a],gr[b])]]--;
}
for(int i = 1;i <= n;++i)
{
odw[i] = 0;
//cout << gr[i] << ' ' << wag[gr[i]] << ' ' << wag1[gr[i]] << endl;
}
for(int i = 1;i <= n;++i)
{
if(odw[i] == 0)
dfs2(i);
}
for(int i = 1;i <= n;++i)
{
odw[i] = 0;
}
for(int i = 1;i <= n;++i)
{
if(odw[i] == 0)
dfs3(i);
}
for(int i = 2;i <= n;++i)
{
//////cout << wag[gr[i]] << ' ';
if(wag[gr[i]] > 0 && dok[i] > 0)
{
if(gr[i] != gr[dok[i]])
{
////cout << k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}].first << ' ' << k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}].second << endl;
wyn[k1[k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}]]] = 1;
if(pls.find({i,dok[i]}) == pls.end())
{
wyn[k1[k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}]]] = 2;
}
}
}
}
for(int i = 2;i <= n;++i)
{
//////cout << wag1[gr[i]] << ' ';
if(wag1[gr[i]] > 0 && dok[i] > 0)
{
if(gr[i] != gr[dok[i]])
{
////cout << k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}].first << ' ' << k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}].second << endl;
wyn[k1[k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}]]] = 2;
if(pls.find({i,dok[i]}) == pls.end())
{
wyn[k1[k[{min(gr[i],gr[dok[i]]),max(gr[i],gr[dok[i]])}]]] = 1;
}
}
}
}
for(int i = 0;i < m1;++i)
{
//////cout << wyn[i];
if(wyn[i] == 0)
{
cout << 'B';
}
if(wyn[i] == 1)
{
cout << 'R';
}
if(wyn[i] == 2)
{
cout << 'L';
}
}
}
