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

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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

e = A("e")
i = B("i")
h = C("h")
f = D("f")
b = E("b")
a = F("a")
j = F("j")
c = E("c")
g = E("g")
m = B("m")

e.u = m
e.x = h
e.s = f
i.v = b
i.p = m
i.q = a
i.u = f
i.t = e
i.r = j
h.s = j
f.w = h
b.t = f
b.w = i
b.s = a
b.q = j
a.v = i
a.t = f
a.o = f
a.x = e
a.y = m
a.r = g
j.v = i
j.y = i
j.t = f
j.o = f
j.x = e
j.r = b
c.t = f
c.w = m
c.s = j
c.q = j
g.t = f
g.w = i
g.s = a
g.q = a
m.v = c
m.p = i
m.q = j
m.u = f
m.t = e
m.r = a
assert e.u.p.v.w.t.u.u.w.s.txt == "
class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.x: C = None
        self.s: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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

e = A("e")
i = B("i")
h = C("h")
f = D("f")
b = E("b")
a = F("a")
j = F("j")
c = E("c")
g = E("g")
m = B("m")

e.u = m
e.x = h
e.s = f
i.v = b
i.p = m
i.q = a
i.u = f
i.t = e
i.r = j
h.s = j
f.w = h
b.t = f
b.w = i
b.s = a
b.q = j
a.v = i
a.t = f
a.o = f
a.x = e
a.y = m
a.r = g
j.v = i
j.y = i
j.t = f
j.o = f
j.x = e
j.r = b
c.t = f
c.w = m
c.s = j
c.q = j
g.t = f
g.w = i
g.s = a
g.q = a
m.v = c
m.p = i
m.q = j
m.u = f
m.t = e
m.r = a
assert e.u.p.v.w.t.u.u.w.s.txt == "j"