//USE https://mirrorless-camera.info/column/14417.html macro_rules! input { ($($r:tt)*) => { let mut bytes = std::io::Read::bytes(std::io::BufReader::new(std::io::stdin())); let mut next = move |is_word: bool| -> String{ if is_word { bytes .by_ref() .map(|r|r.unwrap() as char) .skip_while(|c|c.is_whitespace()) .take_while(|c|!c.is_whitespace()) .collect() } else { bytes .by_ref() .map(|r|r.unwrap() as char) .skip_while(|c| c == &'\n') .take_while(|c| c != &'\n') .collect() } }; input_inner!{next, $($r)*}; }; } macro_rules! input_inner { ($next:expr) => {}; ($next:expr, ) => {}; ($next:expr, static $var:ident : $t:tt $($rest:tt)*) => { $var = read_value!($next, $t); input_inner!{$next $($rest)*} }; ($next:expr, mut $var:ident : $t:tt $($rest:tt)*) => { let mut $var = read_value!($next, $t); input_inner!{$next $($rest)*} }; ($next:expr, $var:ident : $t:tt $($rest:tt)*) => { let $var = read_value!($next, $t); input_inner!{$next $($rest)*} }; } macro_rules! read_value { ($next:expr, ( $($t:tt),* )) => { ( $(read_value!($next, $t)),* ) }; ($next:expr, [ $t:tt ; all ]) => { { let mut str = $next(false); str.split_whitespace().map(|it| it.parse::<$t>().unwrap()).collect::>() } }; ($next:expr, [ $t:tt ; $len:expr ]) => { (0..$len as usize).map(|_| read_value!($next, $t)).collect::>() }; ($next:expr, chars) => { read_value!($next, String).chars().collect::>() }; ($next:expr, lines) => { { let mut vec = Vec::new(); let mut str = $next(false); while str != "" { vec.push(str); str = $next(false); } vec } }; ($next:expr, line) => { $next(false) }; ($next:expr, usize1) => { read_value!($next, usize) - 1 }; ($next:expr, $t:ty) => { $next(true).parse::<$t>().expect("Parse error") }; } fn main() { input! { n : usize, m : usize, } println!("{}", if n*(n+1)<=m*2 { "Yes" } else { "No" }); }