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

class B:
    def __init__(self, txt: str):
        self.u: A = None
        self.y: F = None
        self.q: D = None
        self.z: C = None
        self.o: F = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: A = None
        self.p: E = None
        self.x: B = None
        self.s: A = None
        self.w: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: D = None
        self.x: D = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: C = None
        self.x: A = None
        self.t: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: A = None
        self.y: F = None
        self.q: D = None
        self.z: C = None
        self.o: F = None
        self.r: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: A = None
        self.p: E = None
        self.x: B = None
        self.s: A = None
        self.w: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: D = None
        self.x: D = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: C = None
        self.x: A = None
        self.t: D = None
        self.txt = txt

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

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