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

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

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.u: C = None
        self.x: F = None
        self.y: E = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.r: C = None
        self.q: A = None
        self.v: C = None
        self.s: H = None
        self.p: F = None
        self.w: C = None
        self.z: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.p: F = None
        self.s: G = None
        self.u: G = None
        self.w: H = None
        self.t: H = None
        self.x: B = None
        self.y: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.w: D = None
        self.z: A = None
        self.y: B = None
        self.u: H = None
        self.q: B = None
        self.t: H = None
        self.x: B = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.u: C = None
        self.x: F = None
        self.y: E = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: G = None
        self.r: C = None
        self.q: A = None
        self.v: C = None
        self.s: H = None
        self.p: F = None
        self.w: C = None
        self.z: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.p: F = None
        self.s: G = None
        self.u: G = None
        self.w: H = None
        self.t: H = None
        self.x: B = None
        self.y: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.w: D = None
        self.z: A = None
        self.y: B = None
        self.u: H = None
        self.q: B = None
        self.t: H = None
        self.x: B = None
        self.txt = txt

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

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

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