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

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

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

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

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

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

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

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

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

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

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

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

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

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

f.y = g
f.s = h
f.q = j
f.x = m
c.p = j
c.u = j
c.z = g
n.u = f
n.p = f
e.y = d
e.v = j
e.t = j
e.w = m
h.t = m
h.y = m
h.o = j
h.v = d
h.u = n
j.o = n
g.t = c
g.o = j
g.v = d
g.y = m
g.u = n
m.p = j
m.u = j
m.z = d
d.t = c
d.y = c
d.o = j
d.v = h
d.u = n
l.t = c
l.y = c
l.o = j
l.v = h
l.u = n
assert e.y.y.z.o.txt == "j"