import numpy.random as rd
import matplotlib.pyplot as plt

def T() :
    c = 1
    while rd.randint(1,7) != 1 :
        c += 1
    return c

def N(n) :
    c = 0
    while n != 0 :
        c += 1
        L = rd.randint(1,7,n)
        k = 0
        for de in L :
            if de != 1 :
                k +=1
        n = k
    return c

def E(n,K) :
    s = 0
    for k in range(K) :
        s += N(n)
    return s/K

X = list(range(1,21))
Y = []
for n in X :
    Y.append(E(n,500))
plt.plot(X,Y)
plt.show()