class A:
    def __init__(self, txt: str):
        self.v: B = None
        self.s: E = None
        self.u: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.o: D = None
        self.u: C = None
        self.w: D = None
        self.z: A = None
        self.r: C = None
        self.p: A = None
        self.v: C = None
        self.txt = txt

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

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

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

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

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

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

b = A("b")
f = B("f")
c = C("c")
n = D("n")
k = E("k")
d = F("d")
m = G("m")
l = H("l")

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

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.o: D = None
        self.u: C = None
        self.w: D = None
        self.z: A = None
        self.r: C = None
        self.p: A = None
        self.v: C = None
        self.txt = txt

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

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

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

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

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

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

b = A("b")
f = B("f")
c = C("c")
n = D("n")
k = E("k")
d = F("d")
m = G("m")
l = H("l")

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