class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.r: E = None
        self.z: E = None
        self.t: B = None
        self.v: F = None
        self.o: B = None
        self.txt = txt

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

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

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

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

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

c = A("c")
b = B("b")
e = C("e")
f = D("f")
j = E("j")
d = F("d")
a = F("a")
l = A("l")

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

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

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

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

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

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

c = A("c")
b = B("b")
e = C("e")
f = D("f")
j = E("j")
d = F("d")
a = F("a")
l = A("l")

c.x = a
c.v = a
c.r = j
c.z = j
c.t = b
c.o = b
b.z = e
b.y = e
b.t = d
b.x = d
e.y = a
e.q = d
e.v = f
e.p = f
e.o = f
e.u = j
f.s = l
f.w = e
f.u = j
j.t = e
j.u = b
j.r = b
j.v = d
j.o = f
j.s = f
d.o = b
d.y = l
d.q = f
d.x = f
d.p = f
d.u = e
a.o = b
a.y = c
a.q = f
a.x = f
a.p = f
a.u = e
l.x = a
l.r = j
l.z = j
l.t = b
l.o = b
l.v = d
assert d.u.v.u.t.y.o.txt == "b"