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

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

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

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

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.v: H = None
        self.w: G = None
        self.p: C = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.v: H = None
        self.w: G = None
        self.p: C = None
        self.txt = txt

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

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