class A:
    def __init__(self, txt: str):
        self.t: I = None
        self.u: F = None
        self.r: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: G = None
        self.x: G = None
        self.z: F = None
        self.t: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: D = None
        self.r: D = None
        self.q: D = None
        self.w: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: J = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.o: A = None
        self.x: C = None
        self.u: B = None
        self.s: J = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.w: E = None
        self.x: I = None
        self.v: A = None
        self.q: I = None
        self.y: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: G = None
        self.x: G = None
        self.z: F = None
        self.t: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: D = None
        self.r: D = None
        self.q: D = None
        self.w: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: J = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.o: A = None
        self.x: C = None
        self.u: B = None
        self.s: J = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.w: E = None
        self.x: I = None
        self.v: A = None
        self.q: I = None
        self.y: F = None
        self.txt = txt

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

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