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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: B = None
        self.w: F = None
        self.s: F = None
        self.q: B = None
        self.txt = txt

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: B = None
        self.w: F = None
        self.s: F = None
        self.q: B = None
        self.txt = txt

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

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