class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.w: G = None
        self.y: C = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.o: E = None
        self.z: C = None
        self.s: F = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: C = None
        self.y: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.v: A = None
        self.t: E = None
        self.y: C = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.s: D = None
        self.p: A = None
        self.u: I = None
        self.z: C = None
        self.v: D = None
        self.q: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.s: G = None
        self.r: F = None
        self.v: F = None
        self.u: B = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.o: E = None
        self.z: C = None
        self.s: F = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: G = None
        self.z: C = None
        self.y: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.z: A = None
        self.v: A = None
        self.t: E = None
        self.y: C = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.s: D = None
        self.p: A = None
        self.u: I = None
        self.z: C = None
        self.v: D = None
        self.q: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: C = None
        self.s: G = None
        self.r: F = None
        self.v: F = None
        self.u: B = None
        self.txt = txt

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

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