Please, who solved this problem with disjoint sets send me your solution to the e-mail which is in my profile.
I wrote the code and it gives right answers on many tests, but not passes here. I need to compare where an error is.

Thanks to all, no need anymore. I AC.

For those who has not overcame the problem, i repeat (based on all of the advices i've read here) breafly where you may be wrong

1) if b>length, the friend lies

2) number of questions can be wrong. I read line by line and analyze if there is only one "word" or three. So, to determine where the next test begins i do NOT do like
for(i=0; i<answers; ++i)
but like
while(scanf("%d%d%s",&a,&b,&oddeven) == 3)

But so you all will receive 2 words from next lines, except for last ones.

icanwin, of course i would. But if to be more precisely i do like this:

gets(buf);
if(sscanf(buf, "%d%d%s", &a, &b, oddeven) == 1)
{
  if a == -1 then the end of input
  else a new test begins
}

can you please share your solutions with me

could you please share your solutions with us?