This is my tests:

<Test 1>
input:
10 5
8
1 0
2 0
3 1
4 1
5 0
6 0
15 1
16 1
output:
No reason
5 15
6 16
1 3
2 4

<Test 2>
input:
11 1
18
1 0
2 0
3 0
4 0
6 0
7 0
8 0
9 0
11 0
12 1
13 1
14 1
15 1
16 1
17 1
18 1
19 1
20 1
output:
Liar

<Test 3>
input:
4 2
8
7 0
8 0
9 0
19 1
20 0
21 1
22 1
23 1
output:
No reason
20 21
7 19
8 23
9 22

Edited by author 29.03.2023 21:01

input:
6 3
8
1 0
2 0
3 0
4 0
5 1
7 1
10 1
12 1

output:
No reason
1 10
2 5
3 12
4 7

Max bipartite matching algo works fine for O(VE).

I have solved it using max bipartite matching. Is there any better idea?

Are all the time-stamps recorded by the sensor guaranteed to be unique? I think this is implied by the fact that they are "increasing" (rather than "non-decreasing") but wanted to check.