class A:
    def __init__(self, txt: str):
        self.y: C = None
        self.s: H = None
        self.r: C = None
        self.w: G = None
        self.u: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: F = None
        self.u: I = None
        self.y: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: D = None
        self.u: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: A = None
        self.o: H = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: A = None
        self.q: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: A = None
        self.p: D = None
        self.s: H = None
        self.v: A = None
        self.q: B = None
        self.u: H = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: G = None
        self.v: E = None
        self.y: I = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: F = None
        self.u: I = None
        self.y: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: D = None
        self.u: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: A = None
        self.o: H = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: A = None
        self.q: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: A = None
        self.p: D = None
        self.s: H = None
        self.v: A = None
        self.q: B = None
        self.u: H = None
        self.z: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: G = None
        self.v: E = None
        self.y: I = None
        self.txt = txt

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

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

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