Task: Question Decomposition
Input (English): question: Abuja is capital of which country of the Sahel where the Niger River flows through?
Output (English): #1 return the  Sahel 
#2 return countries of #1 
#3 return capitals of #2 
#4 return #2 where #3 is Abuja 
#5 return #4 where the  Niger River flows through