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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.t: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.p: B = None
        self.w: F = None
        self.y: I = None
        self.o: F = None
        self.t: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.t: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.p: B = None
        self.w: F = None
        self.y: I = None
        self.o: F = None
        self.t: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

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