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

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.o: G = None
        self.s: F = None
        self.y: F = None
        self.z: F = None
        self.w: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: C = None
        self.v: E = None
        self.u: A = None
        self.y: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.o: G = None
        self.s: F = None
        self.y: F = None
        self.z: F = None
        self.w: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.p: C = None
        self.v: E = None
        self.u: A = None
        self.y: B = None
        self.txt = txt

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

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