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

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

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

class D:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: D = None
        self.txt = txt

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

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

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

d = A("d")
b = B("b")
l = C("l")
i = D("i")
j = E("j")
k = F("k")
g = G("g")
n = E("n")
a = D("a")
c = B("c")

d.z = b
d.p = b
d.t = l
b.v = l
b.u = j
b.z = d
b.y = a
l.q = g
l.r = g
l.s = n
l.x = j
i.w = d
i.s = a
j.r = d
j.u = n
j.w = a
j.z = a
j.p = g
k.x = j
k.o = a
k.v = b
g.y = n
g.s = c
g.q = l
n.r = d
n.u = j
n.w = a
n.z = i
n.p = g
a.w = d
a.s = i
c.v = l
c.u = n
c.z = d
c.y = i
assert a.w.z.u.txt == "
class A:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: C = None
        self.p: B = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: D = None
        self.txt = txt

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

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

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

d = A("d")
b = B("b")
l = C("l")
i = D("i")
j = E("j")
k = F("k")
g = G("g")
n = E("n")
a = D("a")
c = B("c")

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