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

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

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: A = None
        self.x: G = None
        self.s: D = None
        self.o: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: A = None
        self.r: G = None
        self.v: G = None
        self.u: A = None
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.o: A = None
        self.r: A = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.p: A = None
        self.x: G = None
        self.s: D = None
        self.o: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: A = None
        self.r: G = None
        self.v: G = None
        self.u: A = None
        self.y: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.o: A = None
        self.r: A = None
        self.txt = txt

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

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

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