public void addNeighbour(int i, int j, int k, int l, int m, int n, Town[] towns) {
		neighbours.add(towns[i]);
		neighbours.add(towns[j]);
		neighbours.add(towns[k]);
		neighbours.add(towns[l]);
		neighbours.add(towns[m]);
		neighbours.add(towns[n]);
		
		// Teste d'abord si la ville n'est pas nulle (<=> la ville fictive utilisee pour simplifier les expressions).
		if (towns[i] != null) towns[i].addNeighbour(this);
		if (towns[j] != null) towns[j].addNeighbour(this);
		if (towns[k] != null) towns[k].addNeighbour(this);
		if (towns[l] != null) towns[l].addNeighbour(this);
		if (towns[m] != null) towns[m].addNeighbour(this);
		if (towns[n] != null) towns[n].addNeighbour(this);
	}