class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.z: C = None
        self.x: D = None
        self.v: D = None
        self.p: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: C = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: B = None
        self.v: D = None
        self.o: C = None
        self.s: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: C = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.u: B = None
        self.v: D = None
        self.o: C = None
        self.s: F = None
        self.txt = txt

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

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