sorting array with condition (paths sorting)

i want sort function to sort the element of matrix except the 1&2 column still fixed. depending at the length of each row (except 0)

like that

a=[1 2 5 2 1 0 0          

   1 2 3 4 0 0 0

   1 2 4 0 0 0 0

   1 3 2 0 0 0 0

   1 3 3 1 4 0 0 

   1 3 4 5 0 0 0

   2 1 4 5 0 0 0

   2 1 3 0 0 0 0]

the first row contain 3 element (after 1&2 column except 0)

the second row contain 2 element

the third row contain 1 element

after sorting

a= [ 1 2 4 0 0 0 0

     1 2 3 4 0 0 0

     1 2 5 2 1 0 0

     1 3 2 0 0 0 0

     1 3 4 5 0 0 0

     1 3 3 1 4 0 0

     2 1 3 0 0 0 0

     2 1 4 5 0 0 0]

Answer 1

[Matt J]

 b=[a,sum(logical(a),2)]; 
 result=sortrows(b,[1,2,size(b,2)]); 
 result(:,end)=[]

[mohammed sportman]

thanks thanks Matt . i am very happy .