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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.r: H = None
        self.z: I = None
        self.q: F = None
        self.s: H = None
        self.v: A = None
        self.y: I = None
        self.p: H = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.v: B = None
        self.y: I = None
        self.u: A = None
        self.p: A = None
        self.s: E = None
        self.w: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: G = None
        self.x: C = None
        self.s: E = None
        self.z: G = None
        self.q: B = None
        self.p: B = None
        self.o: C = None
        self.u: G = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.r: H = None
        self.z: I = None
        self.q: F = None
        self.s: H = None
        self.v: A = None
        self.y: I = None
        self.p: H = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.v: B = None
        self.y: I = None
        self.u: A = None
        self.p: A = None
        self.s: E = None
        self.w: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: C = None
        self.t: G = None
        self.x: C = None
        self.s: E = None
        self.z: G = None
        self.q: B = None
        self.p: B = None
        self.o: C = None
        self.u: G = None
        self.txt = txt

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

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