import numpy as np N,P = map(int,input().split()) data = np.array([list(map(int,input().split())) for _ in range(N)]) print(data) dp = np.zeros((N+1,P+1),int) dp[1,:min(3,P+1)] = data[0,:min(3,P+1)] dp[1:,0] = [data[:i,0].sum() for i in range(1,N+1)] for i in range(N): for j in range(1,P+1): tmp = [] if dp[i,j]!=0:tmp.append(dp[i,j]+data[i,0]) if j-1>=0 and dp[i,j-1]!=0:tmp.append(dp[i,j-1]+data[i,1]) if j-2>=0 and dp[i,j-2]!=0:tmp.append(dp[i,j-2]+data[i,2]) if tmp:dp[i+1,j] = min(tmp) print(min(1.,dp[:,P].min()/N))