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

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.q: F = None
        self.u: C = None
        self.t: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: B = None
        self.w: D = None
        self.v: D = None
        self.s: E = None
        self.r: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: G = None
        self.t: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.v: A = None
        self.w: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.q: F = None
        self.u: C = None
        self.t: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: B = None
        self.w: D = None
        self.v: D = None
        self.s: E = None
        self.r: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: G = None
        self.t: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: E = None
        self.v: A = None
        self.w: A = None
        self.txt = txt

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

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