// -*- coding:utf-8-unix -*- // #![feature(map_first_last)] #![allow(dead_code)] #![allow(unused_imports)] #![allow(unused_macros)] use core::num; use std::any::Any; use std::cmp::Ordering::*; use std::collections::btree_map::Values; use std::collections::*; use std::convert::*; use std::convert::{From, Into}; use std::error::Error; use std::f32::consts::E; use std::fmt::Debug; use std::fmt::Display; use std::fs::File; use std::hash::Hash; use std::io::prelude::*; use std::io::*; use std::iter::Filter; use std::iter::FromIterator; use std::marker::Copy; use std::mem::*; use std::ops::BitAnd; use std::ops::Bound::*; use std::ops::RangeBounds; use std::ops::{Add, Mul, Neg, Sub}; use std::process; use std::slice::from_raw_parts; use std::str; use std::vec; const INF: i64 = 1223372036854775807; const UINF: usize = INF as usize; const LINF: i64 = 2147483647; const INF128: i128 = 1223372036854775807000000000000; // const MOD: i64 = 1000000007; const MOD: i64 = 998244353; const UMOD: usize = MOD as usize; const M_PI: f64 = 3.14159265358979323846; // const MOD: i64 = INF; use std::cmp::*; use std::collections::*; use std::io::stdin; use std::io::stdout; use std::io::Write; macro_rules! p { ($x:expr) => { println!("{}", $x); }; } macro_rules! d { ($x:expr) => { println!("{:?}", $x); }; } fn main() { solve(); } // use str::Chars; #[allow(dead_code)] fn read() -> T { let mut s = String::new(); std::io::stdin().read_line(&mut s).ok(); s.trim().parse().ok().unwrap() } #[allow(dead_code)] fn readi() -> (i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); iter.next().unwrap().parse::().unwrap() } #[allow(dead_code)] fn read_vec() -> Vec { read::() .split_whitespace() .map(|e| e.parse().ok().unwrap()) .collect() } #[allow(dead_code)] fn read_mat(n: u32) -> Vec> { (0..n).map(|_| read_vec()).collect() } #[allow(dead_code)] fn readii() -> (i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readiii() -> (i64, i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuu() -> (usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readff() -> (f64, f64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readcc() -> (char, char) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } fn readuuu() -> (usize, usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readiiii() -> (i64, i64, i64, i64) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } #[allow(dead_code)] fn readuuuu() -> (usize, usize, usize, usize) { let mut str = String::new(); let _ = stdin().read_line(&mut str).unwrap(); let mut iter = str.split_whitespace(); ( iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), iter.next().unwrap().parse::().unwrap(), ) } pub struct Dsu { n: usize, // root node: -1 * component size // otherwise: parent parent_or_size: Vec, } impl Dsu { // 0 <= size <= 10^8 is constrained. pub fn new(size: usize) -> Self { Self { n: size, parent_or_size: vec![-1; size], } } pub fn merge(&mut self, a: usize, b: usize) -> usize { assert!(a < self.n); assert!(b < self.n); let (mut x, mut y) = (self.leader(a), self.leader(b)); if x == y { return x; } if -self.parent_or_size[x] < -self.parent_or_size[y] { std::mem::swap(&mut x, &mut y); } self.parent_or_size[x] += self.parent_or_size[y]; self.parent_or_size[y] = x as i32; x } pub fn same(&mut self, a: usize, b: usize) -> bool { assert!(a < self.n); assert!(b < self.n); self.leader(a) == self.leader(b) } pub fn leader(&mut self, a: usize) -> usize { assert!(a < self.n); if self.parent_or_size[a] < 0 { return a; } self.parent_or_size[a] = self.leader(self.parent_or_size[a] as usize) as i32; self.parent_or_size[a] as usize } pub fn size(&mut self, a: usize) -> usize { assert!(a < self.n); let x = self.leader(a); -self.parent_or_size[x] as usize } pub fn groups(&mut self) -> Vec> { let mut leader_buf = vec![0; self.n]; let mut group_size = vec![0; self.n]; for i in 0..self.n { leader_buf[i] = self.leader(i); group_size[leader_buf[i]] += 1; } let mut result = vec![Vec::new(); self.n]; for i in 0..self.n { result[i].reserve(group_size[i]); } for i in 0..self.n { result[leader_buf[i]].push(i); } result .into_iter() .filter(|x| !x.is_empty()) .collect::>>() } } fn solve() { let n: usize = read(); let s: String = read(); let mut v: Vec = s.chars().collect(); let mut vc = vec![0; 3]; let mut vo = vec![0; 3]; let mut vn = vec![0; 3]; for i in 0..n * 3 { if v[i] == 'c' { vc[i % 3] += 1; } else if v[i] == 'o' { vo[i % 3] += 1; } else if v[i] == 'n' { vn[i % 3] += 1; } } let mut res = 0; res += min(vc[0], min(vo[1], vn[2])); res += min(vc[2], min(vo[0], vn[1])); res += min(vc[1], min(vo[2], vn[0])); // d!((vc, vo, vn)); if res * 3 > n { res -= 1; } p!(res); return; }