use std::io::Write; use std::collections::*; type Map = BTreeMap; type Set = BTreeSet; type Deque = VecDeque; fn run() { input! { n: usize, k: usize, p: [(usize1, String); k], } let mut c = vec!['.'; n]; for (x, s) in p { c[x] = s.chars().next().unwrap(); } let mut ans = String::new(); for c in c.chunks(3) { let mut p = vec!['R', 'G', 'B']; p.sort(); for _ in 0..6 { let mut ok = true; for (i, c) in c.iter().enumerate() { if *c != '.' { ok &= p[..=i].contains(&c); } } if ok { break; } next_permutation(&mut p); } ans.extend(p.into_iter()); } ans.truncate(n); println!("{}", ans); } fn main() { run(); } // ---------- begin input macro ---------- // reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 #[macro_export] macro_rules! input { (source = $s:expr, $($r:tt)*) => { let mut iter = $s.split_whitespace(); input_inner!{iter, $($r)*} }; ($($r:tt)*) => { let s = { use std::io::Read; let mut s = String::new(); std::io::stdin().read_to_string(&mut s).unwrap(); s }; let mut iter = s.split_whitespace(); input_inner!{iter, $($r)*} }; } #[macro_export] macro_rules! input_inner { ($iter:expr) => {}; ($iter:expr, ) => {}; ($iter:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($iter, $t); input_inner!{$iter $($r)*} }; } #[macro_export] macro_rules! read_value { ($iter:expr, ( $($t:tt),* )) => { ( $(read_value!($iter, $t)),* ) }; ($iter:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($iter, $t)).collect::>() }; ($iter:expr, chars) => { read_value!($iter, String).chars().collect::>() }; ($iter:expr, bytes) => { read_value!($iter, String).bytes().collect::>() }; ($iter:expr, usize1) => { read_value!($iter, usize) - 1 }; ($iter:expr, $t:ty) => { $iter.next().unwrap().parse::<$t>().expect("Parse error") }; } // ---------- end input macro ---------- // ---------- begin next_permutation ---------- fn next_permutation(a: &mut [T]) -> bool { a.windows(2).rposition(|a| a[0] < a[1]).map_or(false, |x| { let y = a.iter().rposition(|b| a[x] < *b).unwrap(); a.swap(x, y); a[(x + 1)..].reverse(); true }) } // ---------- end next_permutation ----------