class A:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: B = None
        self.r: D = None
        self.w: G = None
        self.p: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: B = None
        self.w: B = None
        self.o: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: A = None
        self.z: G = None
        self.s: A = None
        self.t: G = None
        self.w: E = None
        self.u: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: H = None
        self.y: H = None
        self.t: C = None
        self.x: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: B = None
        self.w: F = None
        self.x: H = None
        self.z: C = None
        self.o: F = None
        self.q: F = None
        self.v: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: J = None
        self.o: G = None
        self.t: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.r: A = None
        self.q: B = None
        self.p: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: B = None
        self.w: B = None
        self.o: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: A = None
        self.z: G = None
        self.s: A = None
        self.t: G = None
        self.w: E = None
        self.u: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: H = None
        self.y: H = None
        self.t: C = None
        self.x: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: B = None
        self.w: F = None
        self.x: H = None
        self.z: C = None
        self.o: F = None
        self.q: F = None
        self.v: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: J = None
        self.o: G = None
        self.t: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.r: A = None
        self.q: B = None
        self.p: G = None
        self.txt = txt

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

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