class A:
    def __init__(self, txt: str):
        self.y: F = None
        self.t: B = None
        self.o: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

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

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

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

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

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