class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.w: E = None
        self.r: C = None
        self.p: F = None
        self.q: D = None
        self.o: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.t: D = None
        self.o: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.q: B = None
        self.x: B = None
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: C = None
        self.u: B = None
        self.q: A = None
        self.t: F = None
        self.v: A = None
        self.txt = txt

m = A("m")
e = B("e")
b = C("b")
k = D("k")
l = E("l")
n = F("n")
a = F("a")
c = D("c")
j = A("j")
i = C("i")

m.z = k
m.q = k
m.w = l
m.r = b
m.p = n
m.o = e
e.v = c
b.p = a
k.v = e
k.o = e
k.t = c
l.v = k
l.q = e
l.x = e
l.y = j
n.o = j
n.v = j
n.s = i
n.u = e
n.q = m
n.t = a
a.o = j
a.s = b
a.u = e
a.q = m
a.v = m
a.t = n
c.v = e
c.o = e
c.t = k
j.z = c
j.w = l
j.r = b
j.p = n
j.q = k
j.o = e
i.p = a
assert c.t.v.v.t.t.t.v.v.t.txt == "
class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.w: E = None
        self.r: C = None
        self.p: F = None
        self.q: D = None
        self.o: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: B = None
        self.t: D = None
        self.o: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.q: B = None
        self.x: B = None
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.s: C = None
        self.u: B = None
        self.q: A = None
        self.t: F = None
        self.v: A = None
        self.txt = txt

m = A("m")
e = B("e")
b = C("b")
k = D("k")
l = E("l")
n = F("n")
a = F("a")
c = D("c")
j = A("j")
i = C("i")

m.z = k
m.q = k
m.w = l
m.r = b
m.p = n
m.o = e
e.v = c
b.p = a
k.v = e
k.o = e
k.t = c
l.v = k
l.q = e
l.x = e
l.y = j
n.o = j
n.v = j
n.s = i
n.u = e
n.q = m
n.t = a
a.o = j
a.s = b
a.u = e
a.q = m
a.v = m
a.t = n
c.v = e
c.o = e
c.t = k
j.z = c
j.w = l
j.r = b
j.p = n
j.q = k
j.o = e
i.p = a
assert c.t.v.v.t.t.t.v.v.t.txt == "k"