// Constrained-Stable-Matching: stable matching with precedence constraints.
// always: z = mpref[j][G[j]]

class ConstrainedStableMatching {
  void ConstrainedStableMatching(int[][] mpref, int[][] rank) {
    int[] G = 0;
    forbidden (j) :
      G[j] == 0
      || (exists i in [0..n-1] : exists k in [0..G[i]] : mpref[j][G[j]] == mpref[i][k] && rank[mpref[j][G[j]]][i] < rank[mpref[j][G[j]]][j])
    =>
      advance : G[j] = G[j] + 1;
  }
}