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

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

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

class D:
    def __init__(self, txt: str):
        self.v: D = None
        self.t: B = None
        self.o: C = None
        self.y: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: D = None
        self.x: D = None
        self.z: D = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.v: D = None
        self.t: B = None
        self.o: C = None
        self.y: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: D = None
        self.x: D = None
        self.z: D = None
        self.txt = txt

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

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

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