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

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.t: G = None
        self.q: F = None
        self.r: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.z: B = None
        self.r: G = None
        self.o: B = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.t: G = None
        self.q: F = None
        self.r: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.z: B = None
        self.r: G = None
        self.o: B = None
        self.txt = txt

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

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

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

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

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