Types: N: int, M: int, s: List[int], t: List[int]
Ranges: 1 ≤ N ≤ 500, 0 ≤ M ≤ 3,000, 1 ≤ s_i, t_i ≤ N
Addtl Info: s_i ≠ t_i, no multi-edges: for all i < j, {s_i, t_i} ≠ {s_j, t_j}, each component of the graph is strongly connected