class A:
    def __init__(self, txt: str):
        self.t: I = None
        self.x: D = None
        self.z: D = None
        self.s: D = None
        self.y: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: C = None
        self.q: F = None
        self.z: C = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: B = None
        self.t: D = None
        self.p: B = None
        self.z: G = None
        self.r: H = None
        self.y: D = None
        self.o: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.w: H = None
        self.y: C = None
        self.v: C = None
        self.o: E = None
        self.q: C = None
        self.z: D = None
        self.t: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: C = None
        self.q: F = None
        self.z: C = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: B = None
        self.t: D = None
        self.p: B = None
        self.z: G = None
        self.r: H = None
        self.y: D = None
        self.o: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.w: H = None
        self.y: C = None
        self.v: C = None
        self.o: E = None
        self.q: C = None
        self.z: D = None
        self.t: F = None
        self.txt = txt

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

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