class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: G = None
        self.q: C = None
        self.z: F = None
        self.r: E = None
        self.t: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.s: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.s: G = None
        self.o: A = None
        self.q: F = None
        self.r: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.y: B = None
        self.r: B = None
        self.w: C = None
        self.x: A = None
        self.txt = txt

i = A("i")
m = B("m")
l = C("l")
g = D("g")
d = E("d")
k = F("k")
b = G("b")
f = E("f")
n = G("n")
e = C("e")

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

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

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.s: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.s: G = None
        self.o: A = None
        self.q: F = None
        self.r: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.y: B = None
        self.r: B = None
        self.w: C = None
        self.x: A = None
        self.txt = txt

i = A("i")
m = B("m")
l = C("l")
g = D("g")
d = E("d")
k = F("k")
b = G("b")
f = E("f")
n = G("n")
e = C("e")

i.v = k
i.z = k
i.o = n
i.t = n
i.q = e
i.r = f
m.z = k
m.v = g
l.o = n
l.s = n
g.z = e
g.s = n
g.o = i
g.q = k
g.r = f
d.u = k
d.y = k
d.t = e
k.v = m
k.q = g
b.y = m
b.r = m
b.w = e
b.x = i
f.u = k
f.y = k
f.t = l
n.y = m
n.r = m
n.w = l
n.x = i
e.o = n
e.s = n
assert k.v.z.q.o.txt == "i"