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

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

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.s: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: F = None
        self.p: B = None
        self.w: E = None
        self.u: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: E = None
        self.s: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: D = None
        self.y: F = None
        self.p: B = None
        self.w: E = None
        self.u: F = None
        self.txt = txt

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

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