struct Scanner { bytes: std::io::Bytes>, } impl Scanner { fn new() -> Self { Self { bytes: std::io::Read::bytes(std::io::BufReader::new(std::io::stdin())), } } fn next(&mut self) -> String { self.bytes .by_ref() .map(|r| r.unwrap() as char) .skip_while(|c| c.is_whitespace()) .take_while(|c| !c.is_whitespace()) .collect() } } macro_rules! input { ($sc:expr, $($r:tt)*) => { input_inner!{$sc, $($r)*} }; } macro_rules! input_inner { ($sc:expr) => {}; ($sc:expr, ) => {}; ($sc:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($sc, $t); input_inner!{$sc $($r)*} }; } macro_rules! read_value { ($sc:expr, ( $($t:tt),* )) => { ( $(read_value!($sc, $t)),* ) }; ($sc:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($sc, $t)).collect::>() }; ($sc:expr, Chars) => { read_value!($sc, String).chars().collect::>() }; ($sc:expr, Usize1) => { read_value!($sc, usize) - 1 }; ($sc:expr, $t:ty) => { $sc.next().parse::<$t>().expect("Parse error") }; } fn main() { let mut sc = Scanner::new(); let ans = solve(&mut sc); println!("{}", ans); } fn solve(sc: &mut Scanner) -> i64 { input! { sc, n: usize, } if n == 1 { 7 } else if n == 2 { panic!(); } else { 0 } }