1) There are some branches which have 0 apples. Every such branch
does NOT contain any non-zero branch - this test is impossible:
5 2
1 2 1
1 3 0
3 4 0
3 5 1,
because branch 3 (with 0 apples) contains branch 5 (with 1 apple).

2) If there are some branches with 0 apples, we should IGNORE them
and left from other branches (q - number of zero branches) ones. See
also 1).
For example,
7 5
1 2 1
1 3 0
3 4 0
3 5 0.
2 6 0
2 7 1
There are 4 zero branches. Ignore them - you'll get 2 branches.
1 2 1
2 7 1
From these branches you should left 5(q) - 4(number of zero
branches) = 1 branch. Remove 2 7 1 and you'll get answer: 1.

3) All tests are correct now, but for this problem sometimes I had
Wrong Answer, but it should be Runtime Error.

Why is the answer to 2) 1? Why mustn't I remove the zero-apple branches?

I THINK THE ANSWER TO TEST 1 IS "1",AND THE SECOND IS "2"