class A:
    def __init__(self, txt: str):
        self.v: D = None
        self.s: G = None
        self.q: H = None
        self.x: C = None
        self.t: C = None
        self.u: B = None
        self.o: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: H = None
        self.o: F = None
        self.w: A = None
        self.s: D = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.u: D = None
        self.w: D = None
        self.o: C = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: H = None
        self.o: F = None
        self.w: A = None
        self.s: D = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.u: D = None
        self.w: D = None
        self.o: C = None
        self.txt = txt

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

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

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

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

j.v = k
j.o = k
j.s = i
j.q = l
j.x = m
j.t = m
j.u = e
e.u = l
e.o = b
e.w = j
e.v = j
e.s = k
m.u = e
k.s = f
k.v = m
k.q = b
k.z = e
a.t = f
a.u = k
a.w = k
a.o = m
b.y = n
b.z = f
f.q = n
f.u = m
n.o = j
l.o = j
i.q = l
i.u = m
assert k.s.u.u.txt == "e"