class A:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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

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

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