class A:
    def __init__(self, txt: str):
        self.x: C = None
        self.y: C = None
        self.s: A = None
        self.q: C = None
        self.r: H = None
        self.w: A = None
        self.v: A = None
        self.o: I = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: B = None
        self.x: G = None
        self.y: F = None
        self.v: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: C = None
        self.o: D = None
        self.z: G = None
        self.q: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: D = None
        self.t: D = None
        self.u: B = None
        self.o: H = None
        self.x: D = None
        self.p: E = None
        self.w: H = None
        self.v: C = None
        self.z: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: G = None
        self.w: A = None
        self.r: G = None
        self.q: I = None
        self.x: C = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.r: B = None
        self.x: G = None
        self.y: F = None
        self.v: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: C = None
        self.o: D = None
        self.z: G = None
        self.q: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: D = None
        self.t: D = None
        self.u: B = None
        self.o: H = None
        self.x: D = None
        self.p: E = None
        self.w: H = None
        self.v: C = None
        self.z: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: G = None
        self.w: A = None
        self.r: G = None
        self.q: I = None
        self.x: C = None
        self.txt = txt

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

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

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