class A:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: B = None
        self.y: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.w: F = None
        self.t: B = None
        self.y: B = None
        self.x: B = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.p: E = None
        self.y: D = None
        self.u: F = None
        self.t: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.u: E = None
        self.s: C = None
        self.txt = txt

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

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

c.p = j
c.s = a
c.y = d
l.r = d
l.w = g
l.t = a
l.y = a
l.x = a
l.v = c
i.r = e
d.s = k
d.p = f
d.y = j
d.u = g
d.t = a
e.x = d
e.u = f
e.s = i
g.y = f
g.u = k
f.x = j
f.u = e
f.s = k
k.r = f
a.r = d
a.w = g
a.t = l
a.y = l
a.x = l
a.v = c
j.s = k
j.p = e
j.y = d
j.u = g
j.t = l
assert g.y.s.r.u.s.txt == "
class A:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: B = None
        self.y: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: D = None
        self.w: F = None
        self.t: B = None
        self.y: B = None
        self.x: B = None
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.p: E = None
        self.y: D = None
        self.u: F = None
        self.t: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.u: E = None
        self.s: C = None
        self.txt = txt

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

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

c.p = j
c.s = a
c.y = d
l.r = d
l.w = g
l.t = a
l.y = a
l.x = a
l.v = c
i.r = e
d.s = k
d.p = f
d.y = j
d.u = g
d.t = a
e.x = d
e.u = f
e.s = i
g.y = f
g.u = k
f.x = j
f.u = e
f.s = k
k.r = f
a.r = d
a.w = g
a.t = l
a.y = l
a.x = l
a.v = c
j.s = k
j.p = e
j.y = d
j.u = g
j.t = l
assert g.y.s.r.u.s.txt == "i"