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

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.o: G = None
        self.w: D = None
        self.q: A = None
        self.p: E = None
        self.t: A = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.s: A = None
        self.t: C = None
        self.w: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.o: G = None
        self.w: D = None
        self.q: A = None
        self.p: E = None
        self.t: A = None
        self.txt = txt

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.u: E = None
        self.s: A = None
        self.t: C = None
        self.w: D = None
        self.txt = txt

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

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