Visa required, except for Those who continue their journey to
a third country by the first available flight within 48 hours
and without leaving the airport. Passengers must also hold
tickets with reserved seats and other documents for their
onward journey.
*Note:TWOV is not possible when arriving from a non-Schengen
Member State AND departing to a Schengen Member State
这里面first available flight是说比如我从罗马转机去伦敦，就真得坐下一班去伦敦
的飞机（不管是哪家航空公司），才可以不用签证吗？
