class A:
    def __init__(self, txt: str):
        self.y: E = None
        self.z: H = None
        self.s: C = None
        self.q: D = None
        self.o: F = None
        self.r: D = None
        self.p: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.t: D = None
        self.x: D = None
        self.r: H = None
        self.w: D = None
        self.s: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: H = None
        self.s: H = None
        self.v: F = None
        self.o: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.v: H = None
        self.s: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.z: G = None
        self.w: A = None
        self.t: B = None
        self.o: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: E = None
        self.y: F = None
        self.o: D = None
        self.q: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.t: D = None
        self.x: D = None
        self.r: H = None
        self.w: D = None
        self.s: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: H = None
        self.s: H = None
        self.v: F = None
        self.o: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: C = None
        self.v: H = None
        self.s: C = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.z: G = None
        self.w: A = None
        self.t: B = None
        self.o: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: E = None
        self.y: F = None
        self.o: D = None
        self.q: A = None
        self.txt = txt

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

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