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

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: C = None
        self.v: C = None
        self.z: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.z: F = None
        self.v: A = None
        self.w: A = None
        self.r: A = None
        self.s: D = None
        self.txt = txt

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

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

f = A("f")
h = B("h")
l = C("l")
b = D("b")
d = E("d")
a = F("a")
n = G("n")
k = D("k")
e = F("e")
j = B("j")

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

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: C = None
        self.v: C = None
        self.z: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.z: F = None
        self.v: A = None
        self.w: A = None
        self.r: A = None
        self.s: D = None
        self.txt = txt

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

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

f = A("f")
h = B("h")
l = C("l")
b = D("b")
d = E("d")
a = F("a")
n = G("n")
k = D("k")
e = F("e")
j = B("j")

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