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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.t: B = None
        self.r: B = None
        self.txt = txt

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.t: B = None
        self.r: B = None
        self.txt = txt

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

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