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

class B:
    def __init__(self, txt: str):
        self.o: F = None
        self.t: G = None
        self.v: C = None
        self.p: C = None
        self.s: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: A = None
        self.r: G = None
        self.y: I = None
        self.t: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.o: F = None
        self.v: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.r: I = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.s: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.o: H = None
        self.w: F = None
        self.v: E = None
        self.y: F = None
        self.q: H = None
        self.p: C = None
        self.r: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: A = None
        self.q: A = None
        self.r: G = None
        self.u: A = None
        self.s: D = None
        self.o: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: D = None
        self.w: F = None
        self.s: E = None
        self.t: D = None
        self.u: A = None
        self.txt = txt

d = A("d")
k = B("k")
f = C("f")
l = D("l")
b = E("b")
m = F("m")
i = G("i")
e = H("e")
j = I("j")
a = F("a")

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

class B:
    def __init__(self, txt: str):
        self.o: F = None
        self.t: G = None
        self.v: C = None
        self.p: C = None
        self.s: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: A = None
        self.r: G = None
        self.y: I = None
        self.t: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.o: F = None
        self.v: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.r: I = None
        self.o: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.s: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.o: H = None
        self.w: F = None
        self.v: E = None
        self.y: F = None
        self.q: H = None
        self.p: C = None
        self.r: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: A = None
        self.q: A = None
        self.r: G = None
        self.u: A = None
        self.s: D = None
        self.o: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: D = None
        self.w: F = None
        self.s: E = None
        self.t: D = None
        self.u: A = None
        self.txt = txt

d = A("d")
k = B("k")
f = C("f")
l = D("l")
b = E("b")
m = F("m")
i = G("i")
e = H("e")
j = I("j")
a = F("a")

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