class A:
    def __init__(self, txt: str):
        self.r: D = None
        self.x: D = None
        self.w: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: F = None
        self.o: J = None
        self.q: D = None
        self.x: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.w: E = None
        self.x: C = None
        self.s: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: H = None
        self.z: J = None
        self.x: C = None
        self.o: D = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.p: H = None
        self.s: B = None
        self.o: J = None
        self.z: C = None
        self.t: D = None
        self.r: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.t: F = None
        self.o: J = None
        self.q: D = None
        self.x: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.r: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: F = None
        self.w: E = None
        self.x: C = None
        self.s: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.t: H = None
        self.z: J = None
        self.x: C = None
        self.o: D = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.p: H = None
        self.s: B = None
        self.o: J = None
        self.z: C = None
        self.t: D = None
        self.r: F = None
        self.txt = txt

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

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

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