How many years passed between the Imperial Japanese army invading the Federated Shan States and the Thai army evacuating the two Shan states?
return the  Imperial Japanese army invading the   Federated Shan States ;return the  Thai army evacuating the   two Shan States ;return year of #1 ;return year of #2 ;return difference of #4 and  #3
['select', 'select', 'project', 'project', 'arithmetic']