N, M = map(int, input().split())
ABP = [[1./v for v in map(int,input().split())] for _ in range(N)]
dp = [-float('inf')] * 4096
full_bit = (1 << N) - 1
for _ in range(M + 1):
    ndp = dp.copy()
    ndp[0] = 0.
    for i in range(1, N + 1):
        bi = (1 << i) - 1
        while bi <= full_bit:
            s = 0.
            pi = bi
            while pi > 0:
                pbit = pi & -pi
                pidx = (pbit - 1).bit_length()
                dpi = bi ^ pbit
                a, b, p = ABP[pidx]
                s = max(s, ndp[dpi] + a, (ndp[dpi] + b) * p + dp[bi] * (1. - p))
                pi &= pi - 1
            ndp[bi] = max(ndp[bi], s)
            x = bi & -bi
            y = bi + x
            bi = ((bi & ~y) >> x.bit_length()) | y
    dp = ndp
print(dp[full_bit])