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

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

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.t: F = None
        self.y: A = None
        self.o: G = None
        self.p: E = None
        self.v: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: A = None
        self.z: F = None
        self.u: G = None
        self.v: B = None
        self.r: B = None
        self.p: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: C = None
        self.o: G = None
        self.z: G = None
        self.txt = txt

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

h = A("h")
k = B("k")
e = C("e")
f = D("f")
i = E("i")
a = F("a")
d = G("d")
l = B("l")

h.s = a
k.t = l
k.y = i
k.q = i
e.r = d
e.o = d
e.t = a
e.y = h
e.v = h
e.p = i
f.q = h
f.p = h
f.z = a
f.u = d
f.v = l
f.r = k
i.v = h
i.u = h
a.u = f
a.w = e
a.o = d
a.z = d
d.p = k
l.t = k
l.y = i
l.q = i
assert d.p.q.v.s.txt == "
class A:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.t: F = None
        self.y: A = None
        self.o: G = None
        self.p: E = None
        self.v: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: A = None
        self.z: F = None
        self.u: G = None
        self.v: B = None
        self.r: B = None
        self.p: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: C = None
        self.o: G = None
        self.z: G = None
        self.txt = txt

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

h = A("h")
k = B("k")
e = C("e")
f = D("f")
i = E("i")
a = F("a")
d = G("d")
l = B("l")

h.s = a
k.t = l
k.y = i
k.q = i
e.r = d
e.o = d
e.t = a
e.y = h
e.v = h
e.p = i
f.q = h
f.p = h
f.z = a
f.u = d
f.v = l
f.r = k
i.v = h
i.u = h
a.u = f
a.w = e
a.o = d
a.z = d
d.p = k
l.t = k
l.y = i
l.q = i
assert d.p.q.v.s.txt == "a"