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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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