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

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

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

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

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.txt = txt

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

b = A("b")
l = B("l")
j = C("j")
c = D("c")
e = E("e")
g = F("g")
h = D("h")
i = B("i")
k = A("k")
f = C("f")

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.r: D = None
        self.txt = txt

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

b = A("b")
l = B("l")
j = C("j")
c = D("c")
e = E("e")
g = F("g")
h = D("h")
i = B("i")
k = A("k")
f = C("f")

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