COCI '18 Contest 3 #1 Magnus

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Points: 5
Time limit: 1.0s
Memory limit: 64M

Problem type
Allowed languages
Ada, Assembly, Awk, Brain****, C, C#, C++, COBOL, CommonLisp, D, Dart, F#, Forth, Fortran, Go, Groovy, Haskell, Intercal, Java, JS, Kotlin, Lisp, Lua, Nim, ObjC, OCaml, Octave, Pascal, Perl, PHP, Pike, Prolog, Python, Racket, Ruby, Rust, Scala, Scheme, Sed, Swift, TCL, Text, Turing, VB, Zig

Magnus lost a game of chess to Kile so he found comfort in competitive programming. Very soon, he heard of the iconic COCI competition and decided to try his luck there.

He wrote a mail to Kile: "Dear Kile, please, prepare me for COCI. Magnus".

Kile replied: "You want to participate in COCI? All right, here's your warm-up task. A series of four consecutive letters of some word that make up the subword HONI (Croatian acronym for COCI) is called the HONI-block. I will send you the word of length N and you will throw out as many letters as you want (it might be none as well) so that in the end there are as many HONI-blocks as possible in the word. Kile".

Magnus was very worried and asked you, COCI competitive scene, for help. Help him determine the maximum number of HONI-blocks he can get in the final word.


The first line contains a word of length N (1 \le N \le 100\,000), consisting of uppercase letters of the English alphabet.


In the first and only line print out the required number of HONI-blocks.

Sample Input 1


Sample Output 1


Sample Input 2


Sample Output 2


Explanation for Sample Output 2

By throwing out three letters H, O, N or I Magnus can get the word HONI, which contains one HONI-block.

Sample Input 3


Sample Output 3



  • 2
    Quandray  commented on Aug. 2, 2020, 3:42 p.m.

    I have an Accepted submission for this problem. However, I found it difficult to understand what was required, and the only way that Sample Output 2 made any sense to me, was if the explanation said

    By throwing out three letters H, O, N and I Magnus can get the word HONI, which contains one HONI-block.