#include #include using std::cin; using std::cout; const char endl = '\n'; const int N = 205; int n, ans; bool g[N][N], g2[N][N]; // Tarjan int cnt, dfn[N], low[N]; int scc_cnt, id[N], siz[N]; int dout[N], din[N]; bool vis[N]; std::stack st; void tarjan(int u) { dfn[u] = low[u] = ++cnt; st.push(u); vis[u] = true; for (int i = 1; i <= n; i++) { if (!g[u][i]) continue; if (!dfn[i]) { tarjan(i); low[u] = std::min(low[u], low[i]); } else if (vis[i]) { low[u] = std::min(low[u], dfn[i]); } } if (dfn[u] == low[u]) { scc_cnt++; int v; do { v = st.top(); st.pop(); vis[v] = false; id[v] = scc_cnt; siz[scc_cnt]++; } while (v != u); if (siz[scc_cnt] > 1) ans += siz[scc_cnt]; } } int main() { std::ios::sync_with_stdio(false); cin.tie(nullptr); cin >> n; for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { cin >> g[i][j]; } } for (int i = 1; i <= n; i++) { if (!dfn[i]) tarjan(i); } for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { if (g[i][j] && id[i] != id[j]) { g2[id[i]][id[j]] = true; } } } for (int i = 1; i <= scc_cnt; i++) { for (int j = 1; j <= scc_cnt; j++) { for (int k = 1; k <= scc_cnt; k++) { if (i != j && j != k && g2[i][k] && g2[k][j]) { g2[i][j] = false; } } } } for (int i = 1; i <= scc_cnt; i++) { for (int j = 1; j <= scc_cnt; j++) { if (g2[i][j]) ans++; } } cout << ans << endl; return 0; }