class A:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: G = None
        self.r: A = None
        self.u: H = None
        self.y: B = None
        self.w: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.q: H = None
        self.r: B = None
        self.z: H = None
        self.w: B = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.w: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.u: E = None
        self.t: G = None
        self.y: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: B = None
        self.txt = txt

d = A("d")
j = B("j")
k = C("k")
h = D("h")
l = E("l")
i = F("i")
e = G("e")
a = H("a")
b = E("b")
f = A("f")

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

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

class C:
    def __init__(self, txt: str):
        self.q: H = None
        self.r: B = None
        self.z: H = None
        self.w: B = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.w: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.u: E = None
        self.t: G = None
        self.y: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: B = None
        self.txt = txt

d = A("d")
j = B("j")
k = C("k")
h = D("h")
l = E("l")
i = F("i")
e = G("e")
a = H("a")
b = E("b")
f = A("f")

d.o = i
d.w = i
d.v = e
d.r = f
d.u = a
d.y = j
j.q = k
j.o = i
k.q = a
k.z = a
k.r = j
k.w = j
k.p = b
h.y = e
l.t = k
l.w = i
i.s = a
i.u = b
i.t = e
i.y = d
e.v = j
a.y = j
b.t = k
b.w = i
f.o = i
f.w = i
f.v = e
f.r = d
f.u = a
f.y = j
assert i.t.v.q.p.t.txt == "k"