#include <iostream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iomanip>
#include <unordered_set>
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("O2")
using namespace std;
int timer = 0;
int timer1 = 0;
bool IS_BRIDGE[200000];
void dfs(int v, int p, vector<bool>& used, vector<vector<pair<int, int>>>& g, vector<int>& tin, vector<int>& up)
{
tin[v] = timer++;
up[v] = tin[v];
used[v] = true;
for (pair<int, int> x : g[v])
{
int u = x.first;
int i = x.second;
if (!used[u])
{
dfs(u, v, used, g, tin, up);
up[v] = min(up[v], up[u]);
if (up[u] > tin[v])
{
IS_BRIDGE[i] = true;
}
}
else if (u != p)
{
up[v] = min(up[v], tin[u]);
}
}
}
void dfs1(int v, vector<int>& used, vector<vector<pair<int, int>>>& g, int cnt)
{
used[v] = cnt;
for (pair<int, int> x : g[v])
{
int u = x.first;
int i = x.second;
if (!IS_BRIDGE[i] && !used[u])
{
dfs1(u, used, g, cnt);
}
}
}
int par[17][100000];
int h[100000];
void dfs2(int v, int p, vector<bool>& used, vector<int>& tin, vector<int>& tout, vector<vector<int>>& g)
{
used[v] = true;
par[0][v] = p;
if (p == v)
h[v] = 0;
else
h[v] = h[p] + 1;
for (int i = 1; i < 17; ++i)
{
par[i][v] = par[i - 1][par[i - 1][v]];
}
tin[v] = timer1++;
for (int u : g[v])
{
if (!used[u])
{
dfs2(u, p, used, tin, tout, g);
}
}
tout[v] = timer1++;
}
bool ok(int a, int b, vector<int>& tin, vector<int>& tout)
{
if (tin[a] <= tin[b] && tout[a] >= tout[b]) return true;
return false;
}
int get_lca(int a, int b, vector<int>& tin, vector<int>& tout)
{
for (int i = 16; i >= 0; --i)
{
if (!ok(par[i][a], b, tin, tout))
{
a = par[i][a];
}
}
a = par[0][a];
return a;
}
void dfs3(int v, vector<bool>& used, vector<vector<int>>& g, vector<int>& lol, int w)
{
h[v] = w;
used[v] = true;
for (int u : g[v])
{
if (!used[u])
{
dfs3(u, used, g, lol, w + 1);
lol[v] += lol[u];
}
}
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n, m;
cin >> n >> m;
for (int i = 0; i < m; ++i)
{
IS_BRIDGE[i] = false;
}
vector<vector<pair<int, int>>> g(n);
vector<int> ans(m, 0);
map<pair<int, int>, int> d;
vector<pair<int, int>> e;
for (int i = 0; i < m; ++i)
{
int u, v;
cin >> u >> v;
--u; --v;
e.push_back({ u, v });
if (u > v) swap(u, v);
if (d.count({ u, v }))
{
ans[d[{u, v}]] = -1;
}
d[{u, v}] = i;
g[u].push_back({ v, i });
g[v].push_back({ u, i });
}
vector<bool> used(n, false);
vector<int> tin(n), up(n);
for (int i = 0; i < n; ++i)
{
if (!used[i])
{
dfs(i, -1, used, g, tin, up);
}
}
for (int i = 0; i < m; ++i)
{
if (IS_BRIDGE[i] && ans[i] == -1)
{
IS_BRIDGE[i] = false;
}
if (!IS_BRIDGE[i])
{
ans[i] = -1;
}
//cout << IS_BRIDGE[i] << ' ';
}
vector<vector<int>> g1(n);
vector<int> used1(n, 0);
int cnt = 1;
for (int i = 0; i < n; ++i)
{
if (!used1[i])
{
dfs1(i, used1, g, cnt++);
}
}
for (int i = 0; i < n; ++i)
{
--used1[i];
}
g1.resize(cnt - 1);
for (int i = 0; i < n; ++i)
{
for (pair<int, int> x : g[i])
{
int u = x.first;
int j = x.second;
if (IS_BRIDGE[j])
{
g1[used1[i]].push_back(used1[u]);
g1[used1[u]].push_back(used1[i]);
}
}
}
vector<bool> used2(cnt, false);
vector<int> tout(cnt);
vector<int> lol(cnt, 0);
tin.resize(cnt);
for (int i = 0; i < cnt - 1; ++i)
{
if (!used2[i])
{
dfs2(i, 0, used2, tin, tout, g1);
}
}
int p;
cin >> p;
for (int i = 0; i < p; ++i)
{
int u, v;
cin >> u >> v;
--u; --v;
u = used1[u];
v = used1[v];
lol[u] += -1;
lol[v] += 1;
}
used2.assign(cnt, false);
for (int i = 0; i < cnt - 1; ++i)
{
if (!used2[i])
{
dfs3(i, used2, g1, lol, 0);
}
}
for (int i = 0; i < m; ++i)
{
int u = e[i].first;
int v = e[i].second;
u = used1[u];
v = used1[v];
//cout << i << ' ' << u << ' ' << v << ' ' << lol[u] << ' ' << lol[v] << endl;
if ((h[u] > h[v] && lol[u] != 0) || (h[v] > h[u] && lol[v] != 0))
{
if (h[u] > h[v] && lol[u] < 0)
{
ans[i] = 1;
}
else if (h[u] > h[v] && lol[u] > 0)
{
ans[i] = 2;
}
else if (h[u] < h[v] && lol[v] < 0)
{
ans[i] = 2;
}
else if (h[u] < h[v] && lol[v] > 0)
{
ans[i] = 1;
}
}
else
{
ans[i] = -1;
}
}
for (int i : ans)
{
if (i == -1)
{
cout << 'B';
}
else if (i == 1)
{
cout << 'R';
}
else
{
cout << 'L';
}
}
}
