class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: B = None
        self.t: B = None
        self.o: B = None
        self.r: F = None
        self.q: G = None
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.s: D = None
        self.w: A = None
        self.x: D = None
        self.o: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.z: E = None
        self.t: E = None
        self.v: A = None
        self.s: D = None
        self.p: D = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

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

c = A("c")
g = B("g")
d = C("d")
n = D("n")
e = E("e")
i = F("i")
f = G("f")
j = E("j")
h = D("h")
a = G("a")

c.s = j
c.v = g
c.t = g
c.o = g
c.r = i
c.x = i
c.q = f
g.z = h
g.x = h
g.s = n
g.o = n
g.w = c
d.z = g
n.r = a
n.z = j
n.t = j
n.v = c
n.s = h
n.p = h
e.r = c
e.z = n
e.o = n
e.s = a
e.p = a
i.u = e
f.w = g
f.o = g
f.r = e
f.s = e
f.q = n
f.p = c
j.r = c
j.z = n
j.s = a
j.p = a
j.o = h
h.r = f
h.z = e
h.t = e
h.v = c
h.s = n
h.p = n
a.w = g
a.o = g
a.r = j
a.s = j
a.q = n
a.p = c
assert i.u.s.s.z.s.r.p.x.u.txt == "
class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.v: B = None
        self.t: B = None
        self.o: B = None
        self.r: F = None
        self.q: G = None
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.s: D = None
        self.w: A = None
        self.x: D = None
        self.o: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: G = None
        self.z: E = None
        self.t: E = None
        self.v: A = None
        self.s: D = None
        self.p: D = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.txt = txt

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

c = A("c")
g = B("g")
d = C("d")
n = D("n")
e = E("e")
i = F("i")
f = G("f")
j = E("j")
h = D("h")
a = G("a")

c.s = j
c.v = g
c.t = g
c.o = g
c.r = i
c.x = i
c.q = f
g.z = h
g.x = h
g.s = n
g.o = n
g.w = c
d.z = g
n.r = a
n.z = j
n.t = j
n.v = c
n.s = h
n.p = h
e.r = c
e.z = n
e.o = n
e.s = a
e.p = a
i.u = e
f.w = g
f.o = g
f.r = e
f.s = e
f.q = n
f.p = c
j.r = c
j.z = n
j.s = a
j.p = a
j.o = h
h.r = f
h.z = e
h.t = e
h.v = c
h.s = n
h.p = n
a.w = g
a.o = g
a.r = j
a.s = j
a.q = n
a.p = c
assert i.u.s.s.z.s.r.p.x.u.txt == "e"