class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: I = None
        self.o: G = None
        self.y: D = None
        self.z: H = None
        self.w: F = None
        self.v: G = None
        self.t: D = None
        self.q: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: A = None
        self.u: E = None
        self.z: F = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.y: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.t: F = None
        self.w: E = None
        self.v: E = None
        self.y: E = None
        self.x: F = None
        self.r: H = None
        self.txt = txt

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

j.s = a
i.y = c
a.p = k
a.o = n
a.v = n
a.y = l
a.t = l
a.z = m
a.w = c
a.q = i
l.v = c
l.z = c
l.y = j
l.u = f
f.v = n
c.r = j
c.o = n
c.s = k
n.q = a
m.s = k
m.y = l
k.p = l
k.t = c
k.x = c
k.w = f
k.v = f
k.y = f
k.r = m
assert c.o.q.w.r.s.txt == "
class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.p: I = None
        self.o: G = None
        self.y: D = None
        self.z: H = None
        self.w: F = None
        self.v: G = None
        self.t: D = None
        self.q: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.y: A = None
        self.u: E = None
        self.z: F = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.y: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: D = None
        self.t: F = None
        self.w: E = None
        self.v: E = None
        self.y: E = None
        self.x: F = None
        self.r: H = None
        self.txt = txt

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

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