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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.v: B = None
        self.x: B = None
        self.s: E = None
        self.w: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.x: D = None
        self.p: C = None
        self.r: A = None
        self.w: D = None
        self.s: F = None
        self.txt = txt

d = A("d")
j = B("j")
l = C("l")
b = D("b")
k = E("k")
e = F("e")
m = G("m")
h = C("h")
f = E("f")
a = B("a")

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: G = None
        self.v: B = None
        self.x: B = None
        self.s: E = None
        self.w: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: F = None
        self.x: D = None
        self.p: C = None
        self.r: A = None
        self.w: D = None
        self.s: F = None
        self.txt = txt

d = A("d")
j = B("j")
l = C("l")
b = D("b")
k = E("k")
e = F("e")
m = G("m")
h = C("h")
f = E("f")
a = B("a")

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