class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.r: G = None
        self.z: D = None
        self.o: B = None
        self.p: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: B = None
        self.o: F = None
        self.p: D = None
        self.z: G = None
        self.s: E = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: G = 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.o: B = None
        self.t: B = None
        self.u: E = None
        self.r: B = None
        self.w: F = None
        self.y: B = None
        self.z: C = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.v: B = None
        self.o: F = None
        self.p: D = None
        self.z: G = None
        self.s: E = None
        self.x: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: G = 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.o: B = None
        self.t: B = None
        self.u: E = None
        self.r: B = None
        self.w: F = None
        self.y: B = None
        self.z: C = None
        self.txt = txt

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

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

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