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

class B:
    def __init__(self, txt: str):
        self.x: D = None
        self.v: E = None
        self.p: E = None
        self.t: E = None
        self.r: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.x: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: G = None
        self.y: C = None
        self.p: A = None
        self.u: A = None
        self.r: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.p: A = None
        self.o: A = None
        self.w: B = None
        self.txt = txt

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

e.o = i
e.r = d
e.u = j
a.x = f
a.v = l
a.p = l
a.t = m
a.r = j
d.p = i
f.v = i
m.r = e
m.x = h
k.t = i
k.r = i
k.y = d
k.p = e
k.u = e
i.y = f
i.p = e
i.o = e
i.w = h
h.x = f
h.v = m
h.p = l
h.t = l
h.r = k
j.t = i
j.r = i
j.y = d
j.p = e
j.u = e
l.r = e
l.x = a
assert e.r.p.y.v.y.v.w.x.txt == "
class A:
    def __init__(self, txt: str):
        self.o: G = None
        self.r: C = None
        self.u: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: D = None
        self.v: E = None
        self.p: E = None
        self.t: E = None
        self.r: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.x: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: G = None
        self.y: C = None
        self.p: A = None
        self.u: A = None
        self.r: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.p: A = None
        self.o: A = None
        self.w: B = None
        self.txt = txt

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

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