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

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.r: E = None
        self.q: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.y: B = None
        self.x: A = None
        self.o: D = None
        self.v: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.u: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.o: C = None
        self.u: B = None
        self.v: A = None
        self.p: D = None
        self.txt = txt

e = A("e")
n = B("n")
g = C("g")
l = D("l")
f = E("f")
d = A("d")
b = B("b")
j = C("j")
k = A("k")
c = C("c")

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

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.r: E = None
        self.q: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.y: B = None
        self.x: A = None
        self.o: D = None
        self.v: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.u: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.o: C = None
        self.u: B = None
        self.v: A = None
        self.p: D = None
        self.txt = txt

e = A("e")
n = B("n")
g = C("g")
l = D("l")
f = E("f")
d = A("d")
b = B("b")
j = C("j")
k = A("k")
c = C("c")

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