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

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

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: A = None
        self.z: E = None
        self.t: A = None
        self.w: B = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: A = None
        self.z: E = None
        self.t: A = None
        self.w: B = None
        self.txt = txt

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

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

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

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

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