Light OJ 1040 - Donation

Problem link - 1040 - Donation

Its a very basic mst problem.

let us try to analyze some test case

2

27 26

1 52

here 

we can see if we keep only the cable with 1 meter then all rooms are connected and we can donate all other cables so the answer becomes (27+26+52+1) - 1 = 105

stdout

Case 1: 105

4

0 1 0 0

1 0 0 0

0 0 0 1

0 0 1 0

here
All rooms are not connected  by a single path so the output will be - 1