class A:
    def __init__(self, txt: str):
        self.q: E = None
        self.x: F = None
        self.p: B = None
        self.y: E = None
        self.o: D = None
        self.z: A = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

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

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

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

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