class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.x: I = None
        self.q: I = None
        self.s: H = None
        self.z: H = None
        self.p: G = None
        self.o: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: H = None
        self.t: I = None
        self.x: D = None
        self.r: A = None
        self.z: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.t: B = None
        self.o: H = None
        self.p: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.v: A = None
        self.o: H = None
        self.s: I = None
        self.w: F = None
        self.t: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: G = None
        self.o: A = None
        self.t: A = None
        self.r: D = None
        self.x: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: H = None
        self.t: I = None
        self.x: D = None
        self.r: A = None
        self.z: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.t: B = None
        self.o: H = None
        self.p: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.v: A = None
        self.o: H = None
        self.s: I = None
        self.w: F = None
        self.t: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: G = None
        self.o: A = None
        self.t: A = None
        self.r: D = None
        self.x: E = None
        self.txt = txt

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

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