class A:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: D = None
        self.s: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.p: G = None
        self.s: C = None
        self.v: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.p: I = None
        self.v: G = None
        self.q: B = None
        self.t: I = None
        self.s: B = None
        self.x: H = None
        self.txt = txt

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

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.p: G = None
        self.s: C = None
        self.v: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.p: I = None
        self.v: G = None
        self.q: B = None
        self.t: I = None
        self.s: B = None
        self.x: H = None
        self.txt = txt

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

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

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