class A:
    def __init__(self, txt: str):
        self.y: B = None
        self.o: D = None
        self.x: F = None
        self.p: F = None
        self.w: E = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: B = None
        self.z: B = None
        self.r: E = None
        self.q: F = None
        self.p: A = None
        self.o: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: C = None
        self.p: C = None
        self.v: D = None
        self.q: A = None
        self.o: G = None
        self.y: G = None
        self.w: C = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: B = None
        self.z: B = None
        self.r: E = None
        self.q: F = None
        self.p: A = None
        self.o: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.x: C = None
        self.p: C = None
        self.v: D = None
        self.q: A = None
        self.o: G = None
        self.y: G = None
        self.w: C = None
        self.txt = txt

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

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

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