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

class B:
    def __init__(self, txt: str):
        self.v: H = None
        self.r: D = None
        self.w: E = None
        self.q: F = None
        self.p: C = None
        self.y: H = None
        self.s: F = None
        self.o: G = None
        self.u: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.u: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: H = None
        self.t: I = None
        self.r: B = None
        self.y: H = None
        self.q: E = None
        self.p: G = None
        self.u: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.w: C = None
        self.z: A = None
        self.v: F = None
        self.r: C = None
        self.u: F = None
        self.y: C = None
        self.q: G = None
        self.o: C = None
        self.txt = txt

c = A("c")
b = B("b")
h = C("h")
m = D("m")
n = E("n")
j = F("j")
d = G("d")
a = H("a")
k = I("k")
l = E("l")

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

class B:
    def __init__(self, txt: str):
        self.v: H = None
        self.r: D = None
        self.w: E = None
        self.q: F = None
        self.p: C = None
        self.y: H = None
        self.s: F = None
        self.o: G = None
        self.u: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.s: H = None
        self.u: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: H = None
        self.t: I = None
        self.r: B = None
        self.y: H = None
        self.q: E = None
        self.p: G = None
        self.u: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.o: C = None
        self.x: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.w: C = None
        self.z: A = None
        self.v: F = None
        self.r: C = None
        self.u: F = None
        self.y: C = None
        self.q: G = None
        self.o: C = None
        self.txt = txt

c = A("c")
b = B("b")
h = C("h")
m = D("m")
n = E("n")
j = F("j")
d = G("d")
a = H("a")
k = I("k")
l = E("l")

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