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

class B:
    def __init__(self, txt: str):
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: G = None
        self.t: B = None
        self.q: G = None
        self.y: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.o: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.t: A = None
        self.u: D = None
        self.w: E = None
        self.o: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: G = None
        self.t: B = None
        self.q: G = None
        self.y: E = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.o: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.t: A = None
        self.u: D = None
        self.w: E = None
        self.o: B = None
        self.txt = txt

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

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