from time import time from heapq import heappop, heappush N, K = map(int, input().split()) A = list(map(int, input().split())) q = [-a for a in A[::-1]] st = set(q) cl = [] t0 = time() while q and time()-t0 < 1.8: a = heappop(q) if a == -1: print("No") exit() elif a > -1: print("Yes") exit() p = [] for a2 in q + cl: if abs(a2-a) in [1, 3, 5]: a3 = ((a2+a)//2)+4 if a < a3 and a3 not in st: p.append(a3) st.add(a3) for a2 in p: heappush(q, a2) cl.append(a) if q: print("No") else: print("Yes")