class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.v: J = None
        self.y: F = None
        self.o: H = None
        self.t: F = None
        self.w: I = None
        self.p: C = None
        self.x: D = None
        self.q: I = None
        self.r: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.v: A = None
        self.w: G = None
        self.t: I = None
        self.u: H = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: D = None
        self.w: D = None
        self.q: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: H = None
        self.v: A = None
        self.txt = txt

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

i.z = d
i.y = d
i.t = d
i.v = g
i.o = k
i.w = c
i.q = c
i.p = n
i.r = n
i.x = l
a.r = i
a.v = i
a.w = h
a.t = c
a.u = k
n.x = h
n.r = l
n.z = g
l.v = k
l.s = c
j.t = h
j.v = h
j.w = g
j.u = g
j.q = g
j.y = c
j.x = n
j.s = i
j.r = d
d.x = c
d.s = l
d.w = l
d.q = i
h.x = i
h.r = l
k.y = d
c.x = j
g.x = k
g.v = i
assert c.x.r.q.q.x.v.x.txt == "
class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.v: J = None
        self.y: F = None
        self.o: H = None
        self.t: F = None
        self.w: I = None
        self.p: C = None
        self.x: D = None
        self.q: I = None
        self.r: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.v: A = None
        self.w: G = None
        self.t: I = None
        self.u: H = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.x: I = None
        self.s: D = None
        self.w: D = None
        self.q: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: H = None
        self.v: A = None
        self.txt = txt

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

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