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

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

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.v: D = None
        self.o: D = None
        self.w: D = None
        self.q: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.s: G = None
        self.q: I = None
        self.x: H = None
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: H = None
        self.w: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: F = None
        self.t: C = None
        self.o: I = None
        self.z: B = None
        self.s: A = None
        self.u: F = None
        self.r: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: G = None
        self.q: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: E = None
        self.s: A = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: I = None
        self.v: D = None
        self.o: D = None
        self.w: D = None
        self.q: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.s: G = None
        self.q: I = None
        self.x: H = None
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: H = None
        self.w: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: F = None
        self.t: C = None
        self.o: I = None
        self.z: B = None
        self.s: A = None
        self.u: F = None
        self.r: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: G = None
        self.q: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: H = None
        self.o: E = None
        self.s: A = None
        self.txt = txt

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

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