Somebody has solved this task? And how it to solve?
I can not any more.
When I check, all normal, but the system shows, that on the fourth test a error.

yes,i have problem with this test(test #4) too.
what is your programe's output on this input?:
20
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
1 4 5 9 2 3 0
10 0
11 0
12 4 5 6 7 8 9 0
13 0
14 0
15 0
16 0
17 0
18 0
2 3 4 5 6 1 7 8 9 10 11 12 13 17 19 0


Edited by author 22.08.2006 13:30