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

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

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: F = None
        self.q: B = None
        self.v: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: E = None
        self.y: B = None
        self.p: E = None
        self.w: E = None
        self.v: E = None
        self.u: E = None
        self.txt = txt

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

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

k.t = b
k.x = e
n.s = c
n.q = e
b.u = n
b.t = n
b.y = c
b.v = h
b.w = m
h.u = c
h.s = c
h.q = n
h.v = e
e.t = f
e.p = f
e.w = f
e.v = f
e.u = f
e.y = n
c.t = k
i.u = n
i.t = n
i.y = c
i.v = h
i.w = m
m.t = l
m.x = e
f.t = e
f.p = e
f.w = e
f.v = e
f.u = e
f.y = n
l.u = n
l.t = n
l.y = c
l.v = h
l.w = k
assert b.y.t.x.p.p.y.s.txt == "
class A:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: E = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.s: F = None
        self.q: B = None
        self.v: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: E = None
        self.y: B = None
        self.p: E = None
        self.w: E = None
        self.v: E = None
        self.u: E = None
        self.txt = txt

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

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

k.t = b
k.x = e
n.s = c
n.q = e
b.u = n
b.t = n
b.y = c
b.v = h
b.w = m
h.u = c
h.s = c
h.q = n
h.v = e
e.t = f
e.p = f
e.w = f
e.v = f
e.u = f
e.y = n
c.t = k
i.u = n
i.t = n
i.y = c
i.v = h
i.w = m
m.t = l
m.x = e
f.t = e
f.p = e
f.w = e
f.v = e
f.u = e
f.y = n
l.u = n
l.t = n
l.y = c
l.v = h
l.w = k
assert b.y.t.x.p.p.y.s.txt == "c"