m = int(input()) a = list(map(int, input().split())) n = int(input()) count = 0 l = [] for i in a: if i == 0: count += 1 else: if count >= 3: l.append(count) count = 0 # 不管怎样都要清零 # 最后一段连续的 0 也要判断 if count >= 3: l.append(count) res = 0 for x in l: if x == 3: res += 1 elif x > 3: res += (x - 3)//2 + 1 print('true' if res >= n else 'false')