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

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

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

class D:
    def __init__(self, txt: str):
        self.o: D = None
        self.t: F = None
        self.r: D = None
        self.u: A = None
        self.q: D = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: B = None
        self.x: E = None
        self.q: E = None
        self.txt = txt

j = A("j")
g = B("g")
k = C("k")
b = D("b")
a = E("a")
l = F("l")
d = D("d")
f = E("f")
c = D("c")

j.s = g
j.t = l
j.u = l
g.u = a
g.s = a
g.v = l
g.q = b
g.w = f
g.y = f
k.v = l
b.o = d
b.q = d
b.t = l
b.r = c
b.u = j
a.x = g
a.w = g
a.q = f
a.s = j
a.z = l
a.t = c
l.o = k
l.r = g
l.x = a
l.q = f
d.o = c
d.r = c
d.q = c
d.t = l
d.u = j
f.x = g
f.w = g
f.q = a
f.s = j
f.z = l
f.t = b
c.o = b
c.t = l
c.r = d
c.q = d
c.u = j
assert f.x.q.o.t.o.v.x.txt == "
class A:
    def __init__(self, txt: str):
        self.s: B = None
        self.t: F = None
        self.u: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.o: D = None
        self.t: F = None
        self.r: D = None
        self.u: A = None
        self.q: D = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: B = None
        self.x: E = None
        self.q: E = None
        self.txt = txt

j = A("j")
g = B("g")
k = C("k")
b = D("b")
a = E("a")
l = F("l")
d = D("d")
f = E("f")
c = D("c")

j.s = g
j.t = l
j.u = l
g.u = a
g.s = a
g.v = l
g.q = b
g.w = f
g.y = f
k.v = l
b.o = d
b.q = d
b.t = l
b.r = c
b.u = j
a.x = g
a.w = g
a.q = f
a.s = j
a.z = l
a.t = c
l.o = k
l.r = g
l.x = a
l.q = f
d.o = c
d.r = c
d.q = c
d.t = l
d.u = j
f.x = g
f.w = g
f.q = a
f.s = j
f.z = l
f.t = b
c.o = b
c.t = l
c.r = d
c.q = d
c.u = j
assert f.x.q.o.t.o.v.x.txt == "a"