private void validateEdges() {
            int[] position = new int[k];
            Arrays.fill(position, s);
            for (int i = 0; i < days; i++) {
                ships.clear();
                for (int j = 0; j < k; j++) {
                    for (Edge edge : g.get(position[j]).edges){
                        if (edge.flow >= 1) {
                            edge.flow -= 1;
                            if (position[j] + n != edge.to) {
                                ships.add(new Pair(j, edge.to % n));
                            }
                            position[j] = edge.to;
                            break;
                        }
                    }
                }

                System.out.print(ships.size() + " ");
                for (Pair ship : ships) {
                    System.out.print(ship.first + 1 + " " + (ship.second + 1) + " ");
                }
                System.out.println();
            }

        }