Problems
 
 
# Name    
A
standard input/output
1 s, 256 MB
Submit  x11
B
standard input/output
3.5 s, 256 MB
Submit  x9
C
standard input/output
1 s, 256 MB
Submit  x51
D
standard input/output
2 s, 256 MB
Submit  
E
standard input/output
2 s, 256 MB
Submit  x2
F
standard input/output
3 s, 256 MB
Submit  
G
standard input/output
3 s, 256 MB
Submit  
H
standard input/output
2 s, 256 MB
Submit  x27
I
AAA
standard input/output
1 s, 256 MB
Submit  x69
J
standard input/output
1 s, 256 MB
Submit  x5
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Questions about problems
 
 
  Question Answer
2026-05-18 13:43:12
Problem H. Prefix MEX
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i still dont understand test 4 it doesnt make any sense i tried all the possibilities
MEX is only 1 value in any set , right?
For example, we can take the prefix [0,1,2] from a and the prefix [5] from b. Then S = {0,1,2,5} and mex(S) = 3, which equals k, so the answer is YES.
2026-05-18 12:58:10
Problem H. Prefix MEX
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what is prefix
A prefix is a contiguous subarray that starts from the first element of the array.

For an array A = [1, 2, 3, 4, 5], the possible non-empty prefixes are:[1] and [1, 2] and [1, 2, 3] and [1, 2, 3, 4] and [1, 2, 3, 4, 5]
2026-05-18 11:54:26
Announcement
General announcement
*****
Some Problems have diffrent time limit than the time stated on the paper

The offical time limit is on website
2026-05-18 11:52:53
Announcement
General announcement
*****
Please Use the "Ask a question"
for any question related to the contest

Please don't ask the volunteer for anything related to the problems