class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: E = None
        self.p: F = None
        self.s: B = None
        self.q: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: D = None
        self.y: B = None
        self.o: A = None
        self.v: E = None
        self.r: E = None
        self.w: E = None
        self.txt = txt

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

e = A("e")
g = B("g")
c = C("c")
b = D("b")
j = E("j")
m = F("m")
k = E("k")

e.s = c
g.z = e
g.t = m
g.u = k
c.y = j
c.p = m
c.s = g
c.q = b
b.p = g
b.y = g
j.p = b
j.y = g
j.o = e
j.v = k
j.r = k
j.w = k
m.w = g
k.p = b
k.y = g
k.o = e
k.v = j
k.r = j
k.w = j
assert g.z.s.s.u.txt == "
class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: E = None
        self.p: F = None
        self.s: B = None
        self.q: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: D = None
        self.y: B = None
        self.o: A = None
        self.v: E = None
        self.r: E = None
        self.w: E = None
        self.txt = txt

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

e = A("e")
g = B("g")
c = C("c")
b = D("b")
j = E("j")
m = F("m")
k = E("k")

e.s = c
g.z = e
g.t = m
g.u = k
c.y = j
c.p = m
c.s = g
c.q = b
b.p = g
b.y = g
j.p = b
j.y = g
j.o = e
j.v = k
j.r = k
j.w = k
m.w = g
k.p = b
k.y = g
k.o = e
k.v = j
k.r = j
k.w = j
assert g.z.s.s.u.txt == "k"