use std::cmp::*; // https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 macro_rules! input { ($($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)*} }; } 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)*} }; } macro_rules! read_value { ($next:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($next, $t)).collect::>() }; ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error")); } trait Change { fn chmax(&mut self, x: Self); fn chmin(&mut self, x: Self); } impl Change for T { fn chmax(&mut self, x: T) { if *self < x { *self = x; } } fn chmin(&mut self, x: T) { if *self > x { *self = x; } } } fn main() { input! { h: usize, w: usize, a: [[i64; w]; h], } let mut dp = vec![vec![[0; 2]; w]; h]; dp[0][0] = [a[0][0]; 2]; for i in 0..h { for j in 0..w { for b in 0..2 { let val = dp[i][j][b]; if i < h - 1 { let x = a[i + 1][j]; if val > x { dp[i + 1][j][b].chmax(val + x); } else if b == 0 { dp[i + 1][j][1].chmax(val); } } if j < w - 1 { let x = a[i][j + 1]; if val > x { dp[i][j + 1][b].chmax(val + x); } else if b == 0 { dp[i][j + 1][1].chmax(val); } } } } } println!("{}", if dp[h - 1][w - 1][1] > a[h - 1][w - 1] { "Yes" } else { "No" }); }