You are the teacher of a class of
students, all but
pairs of which are friends. A friend group is a group of
or
people such that each person in the group is friends with at least
other people in the group. Your next class assignment requires the students to work in groups of
. To "encourage new friendships and social interaction," you want to see if you can pick a group of
that does not contain a friend group. Of course, friendships in the class are constantly evolving. Thus, you would like to determine whether it is still possible to pick a group of
that does not contain a friend group after each of
changes.
Constraints



Subtask 1 [50%]


Subtask 2 [50%]
No additional constraints.
Input Specification
The first line contains
integers
,
, and
.
The next
lines each contain
integers
and
, indicating that students
and
are not friends. All pairs not mentioned here are originally friends.
The next
lines each contain
integers
and
, indicating a change in the friendship status of students
and
; they become friends if they weren't friends previously and vice versa.
Output Specification
Output
lines, the
-th line containing the answer after the first
changes. The answer should be either YES
if it is possible to pick a group of
that does not contain a friend group or NO
otherwise.
Sample Input
Copy
6 3 1
1 2
1 3
2 4
1 2
Sample Output
Copy
YES
NO
Explanation for Sample
Initially, the graph looks like this (with edges denoting a friendship):
It can be shown that there is no friend group within the group of students
. However, after the update:
All groups of
contain a friend group, so it is impossible to pick a group of
that does not contain a friend group.
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