N, P = map(int, input().split())
contests = [list(map(int, input().split())) for _ in range(N)]
dp = [float('inf')] * (P + 1)
dp[0] = 0
for i in range(N):
  a = contests[i]
  for j in range(P, -1, -1):
    tmp = float('inf')
    for k in range(4):
      if k < 3:
        add = a[k]
      else:
        add = 1
      if j - k >= 0:
        tmp = min(tmp, dp[j - k] + add)
    dp[j] = tmp
  #print(dp)
print(dp[P] / N)