#include <iostream> #include <vector> #include <algorithm> #include <set> using namespace std; typedef long long ll; #define st first #define nd second #define f(a, c, b) for (int a = c; b > a; a++) #define pb push_back #define all(a) a.begin(), a.end() #define sz(a) int(a.size()) #define int ll #define DUZO 1000000000000000000 using pii = pair<int, int>; using pll = pair<ll, ll>; using vi = vector<int>; using vvi = vector<vector<int>>; vector<pii> kr; set<pii> musi; set<pii> kr_musi; vvi g; vi dp; vi pre; vvi nie_mosty; vector<pii> mosty; vi na_cyklu; vi odw; vvi g_dw; vi nr_dw; int lnk = 1; int t; int nowy(int v, int ind) { if (kr[ind].st != v) return kr[ind].st; else return kr[ind].nd; } void dfs(int v, int p) { pre[v] = dp[v] = t; odw[v] = 1; t++; for (int ind: g[v]) { if (ind == p) continue; int u = nowy(v, ind); if (!odw[u]) { dfs(u, ind); dp[v] = min(dp[v], dp[u]); } else { dp[v] = min(dp[v], pre[u]); } if (pre[v] < pre[u]) { if (dp[u] <= pre[v]) { nie_mosty[u].pb(ind); nie_mosty[v].pb(ind); } else { mosty.pb({u, v}); } } } } void dfs_nm(int v) { nr_dw[v] = lnk; for (int ind: nie_mosty[v]) { int u = nowy(v, ind); if (nr_dw[u]) continue; dfs_nm(u); } } void dfs_dw(int v, int p) { for (int u: g_dw[v]) { if (u == p) continue; dfs_dw(u, v); if (dp[u] > 0) { musi.insert({u, v}); } else if (dp[u] < 0) { musi.insert({v, u}); } dp[v] += dp[u]; } } void solve() { int n, m; cin >> n >> m; kr.resize(m); g.resize(n + 1); f(i, 0, m) { int u, v; cin >> u >> v; kr[i] = {u, v}; g[u].pb(i); g[v].pb(i); } pre.resize(n + 1); t = 0; dp.resize(n + 1); odw.resize(n + 1); nie_mosty = {}; nie_mosty.resize(n + 1); dfs(1, -1); nr_dw.resize(n + 1, 0); f(i, 1, n + 1) { if (nr_dw[i]) continue; dfs_nm(i); lnk++; } g_dw.resize(lnk); for (auto [c, d]: mosty) { int u = nr_dw[c]; int v = nr_dw[d]; g_dw[u].pb(v); g_dw[v].pb(u); } f(i, 1, lnk) { dp[i] = 0; } int q; cin >> q; f(i, 0, q) { int u, v; cin >> u >> v; u = nr_dw[u]; v = nr_dw[v]; dp[u]++; dp[v]--; } /*cout << "a\n"; f(i, 1, sz(g_dw)) { cout << "wierzcholek " << i << " sasiedzi to: "; for (int ele: g_dw[i]) { cout << ele << " "; } cout << "\n"; }*/ dfs_dw(1, 0); /*for (pii ele: musi) { cout << ele.st << " " << ele.nd << "\n"; }*/ for (auto [c, d]: mosty) { int u = nr_dw[c]; int v = nr_dw[d]; if (musi.count({v, u})) { kr_musi.insert({d, c}); } else if (musi.count({u, v})) { kr_musi.insert({c, d}); } } for (auto [u, v]: kr) { if (kr_musi.count({u, v})) { cout<< "R"; } else if (kr_musi.count({v, u})) { cout << "L"; } else { cout << "B"; } } } int32_t main() { ios_base::sync_with_stdio(0); cin.tie(0); int q = 1; //cin >> q; while (q--) solve(); return 0; }