class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.q: G = None
        self.p: D = None
        self.x: H = None
        self.v: H = None
        self.u: E = None
        self.r: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.q: E = None
        self.z: E = None
        self.y: G = None
        self.s: E = None
        self.t: D = None
        self.w: G = None
        self.p: G = None
        self.txt = txt

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.q: E = None
        self.z: E = None
        self.y: G = None
        self.s: E = None
        self.t: D = None
        self.w: G = None
        self.p: G = None
        self.txt = txt

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: E = None
        self.txt = txt

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

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