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

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

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

class D:
    def __init__(self, txt: str):
        self.v: E = None
        self.y: C = None
        self.x: B = None
        self.t: H = None
        self.r: I = None
        self.p: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: I = None
        self.q: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.p: I = None
        self.v: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.u: D = None
        self.y: F = None
        self.v: D = None
        self.o: G = None
        self.t: G = None
        self.p: F = None
        self.x: D = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.v: E = None
        self.y: C = None
        self.x: B = None
        self.t: H = None
        self.r: I = None
        self.p: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: I = None
        self.q: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: G = None
        self.p: I = None
        self.v: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.u: D = None
        self.y: F = None
        self.v: D = None
        self.o: G = None
        self.t: G = None
        self.p: F = None
        self.x: D = None
        self.txt = txt

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

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

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