n, s, b = gets.chomp.split.map(&:to_i)
h = gets.chomp.split.map(&:to_i)
cur = h[0]
(1...n).each do |i|
    next if cur <= h[i]
    if (cur + b*s) <= h[i]
        cur = h[i]
    else
        puts "No"
        exit
    end
end
puts "Yes"