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

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

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: E = None
        self.r: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.u: H = None
        self.x: D = None
        self.p: A = None
        self.r: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: H = None
        self.s: C = None
        self.v: H = None
        self.t: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.x: C = None
        self.t: F = None
        self.u: D = None
        self.s: I = None
        self.q: A = None
        self.r: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: E = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: E = None
        self.r: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.u: H = None
        self.x: D = None
        self.p: A = None
        self.r: C = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: H = None
        self.s: C = None
        self.v: H = None
        self.t: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.x: C = None
        self.t: F = None
        self.u: D = None
        self.s: I = None
        self.q: A = None
        self.r: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: E = None
        self.txt = txt

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

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