class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.x: B = None
        self.z: F = None
        self.w: I = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: G = None
        self.t: B = None
        self.w: F = None
        self.y: F = None
        self.p: F = None
        self.q: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.v: C = None
        self.r: F = None
        self.u: F = None
        self.t: I = None
        self.p: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.p: B = None
        self.w: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.o: I = None
        self.t: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: E = None
        self.z: H = None
        self.txt = txt

i = A("i")
a = B("a")
k = C("k")
n = D("n")
b = E("b")
e = F("e")
j = G("j")
l = H("l")
c = I("c")

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

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

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

class D:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: G = None
        self.t: B = None
        self.w: F = None
        self.y: F = None
        self.p: F = None
        self.q: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.v: C = None
        self.r: F = None
        self.u: F = None
        self.t: I = None
        self.p: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.p: B = None
        self.w: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.o: I = None
        self.t: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: E = None
        self.z: H = None
        self.txt = txt

i = A("i")
a = B("a")
k = C("k")
n = D("n")
b = E("b")
e = F("e")
j = G("j")
l = H("l")
c = I("c")

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