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

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

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.o: H = None
        self.p: B = None
        self.u: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: H = None
        self.o: F = None
        self.r: H = None
        self.q: C = None
        self.x: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.v: F = None
        self.p: A = None
        self.y: H = None
        self.z: H = None
        self.r: E = None
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.o: H = None
        self.p: B = None
        self.u: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: H = None
        self.o: F = None
        self.r: H = None
        self.q: C = None
        self.x: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.v: F = None
        self.p: A = None
        self.y: H = None
        self.z: H = None
        self.r: E = None
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.txt = txt

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

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

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