#![allow(non_snake_case, unused_must_use, unused_imports)]
use std::io::{self, prelude::*};

fn main() {
    let (stdin, stdout) = (io::read_to_string(io::stdin()).unwrap(), io::stdout());
    let (mut stdin, mut buffer) = (stdin.split_whitespace(), io::BufWriter::new(stdout.lock()));
    macro_rules! input {
        ($t: ty, $n: expr) => {
            (0..$n).map(|_| input!($t)).collect::<Vec<_>>()
        };
        ($t: ty) => {
            stdin.next().unwrap().parse::<$t>().unwrap()
        };
    }

    let N = input!(usize);
    let S = input!(u64);
    let B = input!(u64);
    let H = input!(u64, N);

    let mut max_height = H[0];

    for i in 0..N {
        max_height = std::cmp::max(max_height, H[i] + S * B);

        if i + 1 < N && max_height < H[i + 1] {
            writeln!(buffer, "No");
            return;
        }
    }

    writeln!(buffer, "Yes");
}