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

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

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

class D:
    def __init__(self, txt: str):
        self.u: A = None
        self.p: A = None
        self.r: B = None
        self.s: F = None
        self.x: F = None
        self.t: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.w: C = None
        self.z: D = None
        self.s: F = None
        self.x: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: D = None
        self.q: F = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: A = None
        self.p: A = None
        self.r: B = None
        self.s: F = None
        self.x: F = None
        self.t: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: D = None
        self.w: C = None
        self.z: D = None
        self.s: F = None
        self.x: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: D = None
        self.q: F = None
        self.txt = txt

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

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