using System; using System.Linq; using System.Text; using System.Numerics; using System.Collections; using System.Collections.Generic; public class Program { static void Main(string[] args) { float X, Y; var _in = Console.ReadLine().Split().Select(x => float.Parse(x)).ToList(); X = _in[0]; Y = _in[1]; var N = int.Parse(Console.ReadLine()); var A = Console.ReadLine().Split().Select(x => float.Parse(x)).ToList(); bool ans = true; foreach (var i in Enumerable.Range(0, N - 2)) { if (Y * (A[i] / X) > A[i + 1]) { ans = false; break; } } Console.WriteLine(ans ? "YES" : "NO"); } }