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

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

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.p: A = None
        self.w: B = None
        self.o: A = None
        self.u: D = None
        self.z: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.v: D = None
        self.s: H = None
        self.w: A = None
        self.x: B = None
        self.p: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: D = None
        self.q: A = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.p: A = None
        self.w: B = None
        self.o: A = None
        self.u: D = None
        self.z: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.v: D = None
        self.s: H = None
        self.w: A = None
        self.x: B = None
        self.p: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: D = None
        self.q: A = None
        self.txt = txt

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

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