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

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

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

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

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

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

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

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

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

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

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

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

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

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

f.s = e
f.o = e
f.q = g
b.z = j
b.u = d
b.t = d
b.r = g
b.x = k
b.o = f
j.r = f
l.x = d
h.u = g
h.y = e
g.q = h
g.y = l
g.s = l
g.t = l
g.u = c
g.o = c
c.r = f
e.u = d
e.y = h
d.q = e
d.y = l
d.s = l
d.t = l
d.u = c
d.o = c
k.z = j
k.u = d
k.r = d
k.t = g
k.x = b
k.o = f
assert c.r.o.u.s.x.q.u.u.txt == "c"