class A:
    def __init__(self, txt: str):
        self.z: A = None
        self.x: E = None
        self.s: B = None
        self.t: F = None
        self.txt = txt

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

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

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

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

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

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

e.z = j
e.x = m
e.s = a
e.t = f
i.x = b
i.u = f
i.p = g
b.z = l
b.s = l
b.v = f
b.x = f
b.y = a
g.z = a
g.y = f
g.u = m
g.s = l
m.y = a
m.r = c
m.u = f
m.p = j
f.u = e
f.r = a
f.w = l
a.x = l
a.u = f
a.p = g
l.z = b
l.s = b
l.v = f
l.x = f
l.y = i
j.z = e
j.x = c
j.s = i
j.t = f
c.y = i
c.r = m
c.u = f
c.p = e
assert m.r.p.z.t.r.x.z.y.u.txt == "
class A:
    def __init__(self, txt: str):
        self.z: A = None
        self.x: E = None
        self.s: B = None
        self.t: F = None
        self.txt = txt

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

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

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

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

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

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

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