class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.o: I = None
        self.v: A = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.w: D = None
        self.u: F = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.p: D = None
        self.y: I = None
        self.r: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: G = None
        self.y: A = None
        self.x: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.z: E = None
        self.p: D = None
        self.o: E = None
        self.w: H = None
        self.x: I = None
        self.y: A = None
        self.v: B = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: D = None
        self.u: F = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: B = None
        self.p: D = None
        self.y: I = None
        self.r: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: G = None
        self.y: A = None
        self.x: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: H = None
        self.z: E = None
        self.p: D = None
        self.o: E = None
        self.w: H = None
        self.x: I = None
        self.y: A = None
        self.v: B = None
        self.txt = txt

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

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

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

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