class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.y: A = None
        self.r: B = None
        self.o: E = None
        self.z: A = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.p: A = None
        self.u: D = None
        self.z: C = None
        self.v: D = None
        self.r: F = None
        self.s: E = None
        self.txt = txt

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

l = A("l")
e = B("e")
d = C("d")
n = D("n")
j = E("j")
c = F("c")
i = E("i")
h = A("h")
g = B("g")
f = D("f")

l.s = i
l.o = i
l.y = h
l.z = h
l.r = e
e.v = c
e.q = l
e.p = l
e.s = j
d.w = n
n.t = j
n.r = d
n.w = d
n.v = g
n.o = c
n.u = f
j.p = h
j.u = n
j.v = n
j.z = d
j.r = c
j.s = i
c.t = f
c.w = n
c.r = n
i.p = l
i.u = n
i.z = d
i.v = f
i.r = c
i.s = j
h.s = j
h.o = j
h.y = l
h.z = l
h.r = e
g.v = c
g.q = h
g.s = j
g.p = l
f.t = j
f.r = d
f.w = d
f.v = e
f.o = c
f.u = n
assert f.o.t.r.w.u.o.t.txt == "
class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.y: A = None
        self.r: B = None
        self.o: E = None
        self.z: A = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.p: A = None
        self.u: D = None
        self.z: C = None
        self.v: D = None
        self.r: F = None
        self.s: E = None
        self.txt = txt

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

l = A("l")
e = B("e")
d = C("d")
n = D("n")
j = E("j")
c = F("c")
i = E("i")
h = A("h")
g = B("g")
f = D("f")

l.s = i
l.o = i
l.y = h
l.z = h
l.r = e
e.v = c
e.q = l
e.p = l
e.s = j
d.w = n
n.t = j
n.r = d
n.w = d
n.v = g
n.o = c
n.u = f
j.p = h
j.u = n
j.v = n
j.z = d
j.r = c
j.s = i
c.t = f
c.w = n
c.r = n
i.p = l
i.u = n
i.z = d
i.v = f
i.r = c
i.s = j
h.s = j
h.o = j
h.y = l
h.z = l
h.r = e
g.v = c
g.q = h
g.s = j
g.p = l
f.t = j
f.r = d
f.w = d
f.v = e
f.o = c
f.u = n
assert f.o.t.r.w.u.o.t.txt == "f"