class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: F = None
        self.s: I = None
        self.q: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.q: E = None
        self.v: B = None
        self.t: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: D = None
        self.p: C = None
        self.w: C = None
        self.o: H = None
        self.s: A = None
        self.q: G = None
        self.y: H = None
        self.t: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: B = None
        self.y: F = None
        self.s: C = None
        self.q: F = None
        self.o: C = None
        self.t: C = None
        self.z: A = None
        self.v: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: F = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.q: E = None
        self.v: B = None
        self.t: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: D = None
        self.p: C = None
        self.w: C = None
        self.o: H = None
        self.s: A = None
        self.q: G = None
        self.y: H = None
        self.t: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: B = None
        self.y: F = None
        self.s: C = None
        self.q: F = None
        self.o: C = None
        self.t: C = None
        self.z: A = None
        self.v: C = None
        self.txt = txt

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

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