Help me in solving SPLITMIN problem

i have problem in sample test case 3,

one pile can have 10,23,80 and the other pile can have 105
in this case the difference is minimum which is 8,

but in the sample test 3 answer is 11.

Problem Link: SPLITMIN Problem - CodeChef

its not the difference of sum between piles but its the difference of max values of the piles and if u consider 10,20,80 in one pile and 105 in other then the difference would be 105-80=25