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The following task is a significantly harder version of task Words from the third stage of 16th Polish OI. It wasn't used in the contest itself, but is an extension for those who solved "Words" and want more. :-)
Let
We are interested in the strings of the form
for
This sequence begins with the following strings:
,
,
,
,
,
.
We call the string a substring of the string
if it occurs
in
as a contiguous (i.e. one-block) subsequence.
A sequence of integers
is given.
Your task is to check whether a string of the form
is a substring of
for some
, and if it is,
you shuold find minimal such
.
The first line of the standard input contains a single integer ,
.
The second line of standard input holds
non-negative integers
(
), separated by single spaces.
Your programme should print out lines to the standard output,
one for each test unit.
Your programm should print to standard output minimal non-negative integer
,
such that
is a substring of
, or NIE (no in Polish) if such
doesn't exist.
For the input data:
2 1 2
the correct result is:
4
while for following input data:
2 2 0
the correct answer is
NIE
Explanation of the example:
The string from the first test case is - it is a substring
of
.
In the second test unit there is a string
,
which is not a substring of
for any
.
Task author: Bartosz Walczak.