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

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

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

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: A = None
        self.w: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: F = None
        self.y: F = None
        self.txt = txt

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

b = A("b")
l = B("l")
e = C("e")
m = D("m")
h = E("h")
c = F("c")
a = A("a")

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

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

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

class D:
    def __init__(self, txt: str):
        self.y: F = None
        self.s: A = None
        self.w: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: F = None
        self.y: F = None
        self.txt = txt

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

b = A("b")
l = B("l")
e = C("e")
m = D("m")
h = E("h")
c = F("c")
a = A("a")

b.q = c
b.y = c
b.w = c
b.v = l
b.o = e
l.y = m
l.w = h
l.r = h
l.z = a
l.t = c
e.u = c
e.w = c
e.r = l
m.y = c
m.s = a
m.w = l
h.q = c
h.y = c
c.y = e
a.q = c
a.y = c
a.w = c
a.v = l
a.o = e
assert a.y.y.u.y.txt == "e"