okay,it can be solved using Dynamic Programming
and once one is computed, it can be easily found by going through the table.
and we can write it like
T(12)=T(10)+T(9)
T(10)=T(8)+T(7)
T(9)=T(7)+T(6)
T(8)=T(6)+T(5)
T(7)=T(5)+T(4)
T(6)=T(4)+T(3)
T(5)=T(3)+T(2)
T(4)=T(2)+T(1)
T(3)=T(1)+T(0)
T(2)=T(0)+T(-1)
We need one function call for each unique T(x)
here we need function calls T(-1),T(0),T(1),T(2,)T(3),T(4),T(5),T(6),T(7),T(8),T(9),T(10),T(12)
13 function calls
so it should be the answer