class A:
    def __init__(self, txt: str):
        self.s: B = None
        self.r: B = None
        self.o: B = None
        self.p: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: F = None
        self.w: E = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: D = None
        self.z: A = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: F = None
        self.w: E = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: D = None
        self.z: A = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: E = None
        self.txt = txt

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

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