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

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

class C:
    def __init__(self, txt: str):
        self.q: H = None
        self.u: J = None
        self.z: J = None
        self.x: E = None
        self.t: E = None
        self.v: I = None
        self.r: D = None
        self.w: B = None
        self.s: F = None
        self.y: J = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.v: I = None
        self.y: H = None
        self.q: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: E = None
        self.r: D = None
        self.s: B = None
        self.y: A = None
        self.w: J = None
        self.u: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: J = None
        self.p: J = None
        self.o: B = None
        self.y: F = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: G = None
        self.r: B = None
        self.z: D = None
        self.u: E = None
        self.y: B = None
        self.v: G = None
        self.s: E = None
        self.w: F = None
        self.x: H = None
        self.o: H = None
        self.txt = txt

e = A("e")
b = B("b")
a = C("a")
n = D("n")
g = E("g")
l = F("l")
h = G("h")
j = H("j")
f = I("f")
c = J("c")

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

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

class C:
    def __init__(self, txt: str):
        self.q: H = None
        self.u: J = None
        self.z: J = None
        self.x: E = None
        self.t: E = None
        self.v: I = None
        self.r: D = None
        self.w: B = None
        self.s: F = None
        self.y: J = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.v: I = None
        self.y: H = None
        self.q: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: G = None
        self.x: E = None
        self.r: D = None
        self.s: B = None
        self.y: A = None
        self.w: J = None
        self.u: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: J = None
        self.p: J = None
        self.o: B = None
        self.y: F = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: G = None
        self.r: B = None
        self.z: D = None
        self.u: E = None
        self.y: B = None
        self.v: G = None
        self.s: E = None
        self.w: F = None
        self.x: H = None
        self.o: H = None
        self.txt = txt

e = A("e")
b = B("b")
a = C("a")
n = D("n")
g = E("g")
l = F("l")
h = G("h")
j = H("j")
f = I("f")
c = J("c")

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