#include <vector>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <queue>
using namespace std;
const int MAXN = 3000;
int T, in[MAXN], low[MAXN], instack[MAXN], bs[MAXN];
vector<pair<int, int>> e[MAXN];
vector<pair<int, int>> re[MAXN];
stack<int> st;
vector<vector<int>> SCC;
vector<int> flags;
void dfs(int a) {
instack[a] = 1;
st.push(a);
in[a] = low[a] = ++T;
for(pair<int, int> i : e[a]) {
if(!in[i.first]) {
dfs(i.first);
low[a] = min(low[a], low[i.first]);
} else if(instack[i.first]) {
low[a] = min(low[a], in[i.first]);
}
}
if(in[a] == low[a]) {
int now = -1;
SCC.push_back(vector<int>(0));
do {
now = st.top();
bs[now] = (int)SCC.size() - 1;
st.pop();
instack[now] = 0;
SCC.back().push_back(now);
} while(now != a);
}
}
int C[MAXN];
int find(int a) {
if(C[a] == a) return a;
return C[a] = find(C[a]);
}
vector<set<int>> has_key;
bitset<MAXN> death;
void merge(int a, int b) { //merge a into b
if(find(a) == find(b)) return;
a = find(a);
b = find(b);
C[a] = b;
death[a] = 1;
if(SCC[a].size() > SCC[b].size()) {
SCC[a].swap(SCC[b]);
has_key[a].swap(has_key[b]);
}
for(int i : SCC[a])
SCC[b].push_back(i), bs[i] = b;
for(int i : has_key[a])
has_key[b].insert(i);
}
std::vector<int> find_reachable(std::vector<int> r, std::vector<int> u, std::vector<int> v, std::vector<int> c) {
std::vector<int> ans(r.size(), 0);
int n = r.size(), m = u.size();
for(int i = 0; i < m; i++) {
if(r[u[i]] == c[i])
e[u[i]].push_back(make_pair(v[i], c[i]));
if(r[v[i]] == c[i])
e[v[i]].push_back(make_pair(u[i], c[i]));
}
for(int i = 0; i < n; i++) {
if(!in[i]) {
dfs(i);
}
}
vector<int> ansv;
vector<int> d_in(SCC.size(), 0);
has_key.resize(SCC.size());
for(int i = 0; i < (int)SCC.size(); i++)
for(int j : SCC[i]) {
has_key[i].insert(r[j]);
for(pair<int, int> k : e[j])
if(bs[k.first] != i) {
re[bs[k.first]].push_back(make_pair(i, k.second));
d_in[i]++;
}
}
queue<int> q;
for(int i = 0; i < (int)SCC.size(); i++) {
C[i] = i;
if(d_in[i] == 0)
q.push(i);
}
while(!q.empty()) {
int now = q.front(); q.pop();
for(pair<int, int> i : re[now]) {
if(has_key[find(now)].find(i.second) != has_key[find(now)].end())
merge(now, i.first);//, printf("%d %d\n", now, i.first);
d_in[i.first]--;
if(d_in[i.first] == 0)
q.push(i.first);
}
}
int nmin = MAXN;
for(int i = 0; i < (int)SCC.size(); i++) {
bool flag = 0;
if(C[i] == i) {
flag = 1;
for(int j : SCC[i]) {
// printf("%d\n", j);
for(pair<int, int> k : e[j]) {
if(find(bs[k.first]) != i)
flag = 0;
}
}
}
flags.push_back(flag);
if(flag)
nmin = min(nmin, (int)SCC[i].size());
}
for(int i = 0; i < (int)SCC.size(); i++) {
if(flags[i] && (int)SCC[i].size() == nmin) {
for(int j : SCC[i])
ans[j] = 1;
}
}
return ans;
}
