class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: I = None
        self.w: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: C = None
        self.v: F = None
        self.t: C = None
        self.y: D = None
        self.u: I = None
        self.r: E = None
        self.s: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: I = None
        self.z: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: D = None
        self.y: I = None
        self.q: D = None
        self.s: H = None
        self.r: I = None
        self.t: G = None
        self.txt = txt

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

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

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

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

j.u = h
j.t = m
j.w = g
k.z = g
k.t = g
k.v = h
k.s = h
k.y = c
k.u = m
k.r = e
g.y = j
g.u = l
c.v = m
c.z = e
e.s = j
e.p = j
e.w = i
e.t = h
e.r = g
e.q = l
e.v = l
e.z = c
h.p = e
h.z = c
h.q = c
h.y = m
h.r = m
h.s = i
h.t = l
l.u = h
l.z = k
i.u = m
i.z = k
i.t = k
i.s = k
i.w = j
i.p = l
i.o = c
m.s = j
m.w = e
m.o = c
assert i.z.y.z.s.txt == "
class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.t: I = None
        self.w: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: C = None
        self.v: F = None
        self.t: C = None
        self.y: D = None
        self.u: I = None
        self.r: E = None
        self.s: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: I = None
        self.z: E = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: E = None
        self.z: D = None
        self.y: I = None
        self.q: D = None
        self.s: H = None
        self.r: I = None
        self.t: G = None
        self.txt = txt

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

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

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

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

j.u = h
j.t = m
j.w = g
k.z = g
k.t = g
k.v = h
k.s = h
k.y = c
k.u = m
k.r = e
g.y = j
g.u = l
c.v = m
c.z = e
e.s = j
e.p = j
e.w = i
e.t = h
e.r = g
e.q = l
e.v = l
e.z = c
h.p = e
h.z = c
h.q = c
h.y = m
h.r = m
h.s = i
h.t = l
l.u = h
l.z = k
i.u = m
i.z = k
i.t = k
i.s = k
i.w = j
i.p = l
i.o = c
m.s = j
m.w = e
m.o = c
assert i.z.y.z.s.txt == "j"