#[allow(unused_imports)] use std::cmp::{max, min, Ordering}; #[allow(unused_imports)] use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque}; #[allow(unused_imports)] use std::io::{stderr, stdin, stdout, BufWriter, StdoutLock, Write}; #[allow(unused_imports)] use std::iter::FromIterator; #[allow(unused_imports)] use std::{i64, u64, usize}; #[allow(unused_macros)] macro_rules ! input { ( source = $ s : expr , $ ( $ r : tt ) * ) => { let mut iter = $ s . split_whitespace ( ) ; let mut next = || { iter . next ( ) . unwrap ( ) } ; input_inner ! { next , $ ( $ r ) * } } ; ( $ ( $ r : tt ) * ) => { let stdin = std :: io :: stdin ( ) ; let mut bytes = std :: io :: Read :: bytes ( std :: io :: BufReader :: new ( stdin . lock ( ) ) ) ; let mut next = move || -> String { bytes . by_ref ( ) . map ( | r | r . unwrap ( ) as char ) . skip_while ( | c | c . is_whitespace ( ) ) . take_while ( | c |! c . is_whitespace ( ) ) . collect ( ) } ; input_inner ! { next , $ ( $ r ) * } } ; } #[allow(unused_macros)] macro_rules ! input_inner { ( $ next : expr ) => { } ; ( $ next : expr , ) => { } ; ( $ next : expr , $ var : ident : $ t : tt $ ( $ r : tt ) * ) => { let $ var = read_value ! ( $ next , $ t ) ; input_inner ! { $ next $ ( $ r ) * } } ; ( $ next : expr , mut $ var : ident : $ t : tt $ ( $ r : tt ) * ) => { let mut $ var = read_value ! ( $ next , $ t ) ; input_inner ! { $ next $ ( $ r ) * } } ; } #[allow(unused_macros)] macro_rules ! read_value { ( $ next : expr , ( $ ( $ t : tt ) ,* ) ) => { ( $ ( read_value ! ( $ next , $ t ) ) ,* ) } ; ( $ next : expr , [ $ t : tt ; $ len : expr ] ) => { ( 0 ..$ len ) . map ( | _ | read_value ! ( $ next , $ t ) ) . collect ::< Vec < _ >> ( ) } ; ( $ next : expr , [ $ t : tt ] ) => { { let len = read_value ! ( $ next , usize ) ; ( 0 .. len ) . map ( | _ | read_value ! ( $ next , $ t ) ) . collect ::< Vec < _ >> ( ) } } ; ( $ next : expr , chars ) => { read_value ! ( $ next , String ) . chars ( ) . collect ::< Vec < char >> ( ) } ; ( $ next : expr , bytes ) => { read_value ! ( $ next , String ) . into_bytes ( ) } ; ( $ next : expr , usize1 ) => { read_value ! ( $ next , usize ) - 1 } ; ( $ next : expr , $ t : ty ) => { $ next ( ) . parse ::<$ t > ( ) . expect ( "Parse error" ) } ; } #[allow(dead_code)] struct Writer { s: String, } #[allow(unused_imports)] use std::fmt::Display; #[allow(dead_code)] #[doc = " let mut writer = Writer::new();"] #[doc = " writer.writeln(hoge);"] #[doc = " writer.flush()"] impl Writer { #[allow(dead_code)] pub fn new() -> Writer { Writer { s: String::new() } } #[allow(dead_code)] pub fn flush(&mut self) { print!("{}", self.s); self.s.clear(); } pub fn write(&mut self, x: T) { self.s.push_str(&format!("{}", x)); } pub fn writeln(&mut self, x: T) { self.s.push_str(&format!("{}", x)); self.s.push('\n'); } #[allow(dead_code)] pub fn write_vec(&mut self, xs: &Vec) { if xs.len() == 0 { self.writeln(""); return; } self.write(&format!("{}", xs[0])); for i in 1..xs.len() { self.write(&format!(" {}", xs[i])); } self.writeln(""); } } #[allow(unused_macros)] macro_rules ! dbg { ( $ ( $ a : expr ) ,* ) => { writeln ! ( & mut stderr ( ) , concat ! ( $ ( stringify ! ( $ a ) , " = {:?}, " ) ,* ) , $ ( $ a ) ,* ) . unwrap ( ) ; } } #[allow(dead_code)] const INF_U: u64 = 1_000_000_000_000_000; #[allow(dead_code)] const INF_I: i64 = 1_000_000_000_000_000; #[allow(non_snake_case)] #[allow(dead_code)] fn main() { input! { n: u64 } println!("{}", (n + 2 - 1) / 2); }