class A:
    def __init__(self, txt: str):
        self.o: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: D = None
        self.w: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: C = None
        self.v: D = None
        self.q: G = None
        self.w: C = None
        self.z: D = None
        self.txt = txt

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

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

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

a = A("a")
j = B("j")
g = C("g")
h = D("h")
k = E("k")
f = F("f")
b = G("b")
l = D("l")
n = F("n")

a.o = g
j.p = b
j.v = l
j.w = a
g.s = a
g.o = h
g.q = h
g.v = h
g.z = k
g.p = j
g.y = j
h.x = g
h.w = g
h.v = l
h.z = l
h.q = b
k.y = j
f.s = b
f.q = j
f.u = a
b.x = g
b.q = g
b.u = g
b.r = g
b.o = j
b.s = l
b.p = a
l.x = g
l.w = g
l.v = h
l.z = h
l.q = b
n.s = b
n.q = j
n.u = a
assert n.u.o.v.v.z.z.txt == "
class A:
    def __init__(self, txt: str):
        self.o: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: D = None
        self.w: A = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: C = None
        self.v: D = None
        self.q: G = None
        self.w: C = None
        self.z: D = None
        self.txt = txt

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

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

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

a = A("a")
j = B("j")
g = C("g")
h = D("h")
k = E("k")
f = F("f")
b = G("b")
l = D("l")
n = F("n")

a.o = g
j.p = b
j.v = l
j.w = a
g.s = a
g.o = h
g.q = h
g.v = h
g.z = k
g.p = j
g.y = j
h.x = g
h.w = g
h.v = l
h.z = l
h.q = b
k.y = j
f.s = b
f.q = j
f.u = a
b.x = g
b.q = g
b.u = g
b.r = g
b.o = j
b.s = l
b.p = a
l.x = g
l.w = g
l.v = h
l.z = h
l.q = b
n.s = b
n.q = j
n.u = a
assert n.u.o.v.v.z.z.txt == "l"