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

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

class C:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: F = None
        self.v: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: C = None
        self.t: B = None
        self.q: A = None
        self.p: B = None
        self.v: E = None
        self.u: C = None
        self.txt = txt

f = A("f")
m = B("m")
k = C("k")
j = D("j")
l = E("l")
c = F("c")
e = G("e")
i = A("i")
h = G("h")

f.u = j
f.z = i
f.y = i
f.w = m
f.t = m
f.v = c
m.y = c
m.u = k
m.v = f
k.p = j
k.z = h
j.z = e
j.q = c
j.v = k
l.p = c
l.t = c
l.q = m
l.z = m
c.v = e
e.w = m
e.t = m
e.p = m
e.z = k
e.u = k
e.q = i
e.v = l
i.u = j
i.z = f
i.y = f
i.w = m
i.t = m
i.v = c
h.w = m
h.t = m
h.p = m
h.z = k
h.u = k
h.q = i
h.v = l
assert h.v.z.u.z.q.v.v.txt == "
class A:
    def __init__(self, txt: str):
        self.u: D = None
        self.z: A = None
        self.w: B = None
        self.t: B = None
        self.y: A = None
        self.v: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: G = None
        self.q: F = None
        self.v: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.z: C = None
        self.t: B = None
        self.q: A = None
        self.p: B = None
        self.v: E = None
        self.u: C = None
        self.txt = txt

f = A("f")
m = B("m")
k = C("k")
j = D("j")
l = E("l")
c = F("c")
e = G("e")
i = A("i")
h = G("h")

f.u = j
f.z = i
f.y = i
f.w = m
f.t = m
f.v = c
m.y = c
m.u = k
m.v = f
k.p = j
k.z = h
j.z = e
j.q = c
j.v = k
l.p = c
l.t = c
l.q = m
l.z = m
c.v = e
e.w = m
e.t = m
e.p = m
e.z = k
e.u = k
e.q = i
e.v = l
i.u = j
i.z = f
i.y = f
i.w = m
i.t = m
i.v = c
h.w = m
h.t = m
h.p = m
h.z = k
h.u = k
h.q = i
h.v = l
assert h.v.z.u.z.q.v.v.txt == "e"