class A:
    def __init__(self, txt: str):
        self.z: E = None
        self.v: B = None
        self.y: C = None
        self.s: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: E = None
        self.y: F = None
        self.x: C = None
        self.o: D = None
        self.w: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.y: G = None
        self.t: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: F = None
        self.s: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: D = None
        self.u: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.r: E = None
        self.y: F = None
        self.x: C = None
        self.o: D = None
        self.w: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: E = None
        self.y: G = None
        self.t: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: G = None
        self.x: F = None
        self.s: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.p: D = None
        self.u: D = None
        self.txt = txt

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

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

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