def log(A,B,C):
    th3=0
    th2 = 0
    for d in range(C):
        th1 = (0.1) ** d
        while (B**th2 < A):
            th3 = th2
            th2 += th1
        if (B**th2 == A):
            return th2
        else:
            th2 = th3
    return th2



print(log(2,10,40))