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

class B:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: C = None
        self.y: F = None
        self.s: F = None
        self.v: B = None
        self.txt = txt

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

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

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

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

m = A("m")
c = B("c")
b = C("b")
i = D("i")
k = E("k")
h = F("h")
a = E("a")
f = E("f")
l = B("l")

m.v = b
m.u = a
m.p = i
c.z = l
c.v = l
c.t = b
c.y = h
c.s = h
b.w = l
i.p = b
i.x = a
i.u = c
i.t = k
i.s = h
k.y = i
k.p = i
k.r = i
k.u = b
k.t = h
k.w = h
h.p = i
h.v = l
h.y = k
h.s = c
h.x = b
h.r = m
a.y = i
a.p = i
a.r = i
a.u = b
a.t = h
a.w = h
f.y = i
f.p = i
f.r = i
f.u = b
f.t = h
f.w = h
l.z = c
l.v = c
l.t = b
l.y = h
l.s = h
assert l.t.w.z.z.v.y.v.v.z.txt == "
class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.u: E = None
        self.p: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: B = None
        self.t: C = None
        self.y: F = None
        self.s: F = None
        self.v: B = None
        self.txt = txt

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

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

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

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

m = A("m")
c = B("c")
b = C("b")
i = D("i")
k = E("k")
h = F("h")
a = E("a")
f = E("f")
l = B("l")

m.v = b
m.u = a
m.p = i
c.z = l
c.v = l
c.t = b
c.y = h
c.s = h
b.w = l
i.p = b
i.x = a
i.u = c
i.t = k
i.s = h
k.y = i
k.p = i
k.r = i
k.u = b
k.t = h
k.w = h
h.p = i
h.v = l
h.y = k
h.s = c
h.x = b
h.r = m
a.y = i
a.p = i
a.r = i
a.u = b
a.t = h
a.w = h
f.y = i
f.p = i
f.r = i
f.u = b
f.t = h
f.w = h
l.z = c
l.v = c
l.t = b
l.y = h
l.s = h
assert l.t.w.z.z.v.y.v.v.z.txt == "l"