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

class B:
    def __init__(self, txt: str):
        self.w: D = None
        self.o: F = None
        self.t: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: D = None
        self.y: D = None
        self.txt = txt

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

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

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

f.w = b
k.w = b
k.o = j
k.t = e
n.w = l
n.p = j
l.t = m
l.r = b
l.y = b
e.t = j
e.z = m
e.r = n
e.p = n
e.y = k
e.s = f
j.z = h
j.u = h
j.o = f
j.v = f
b.t = m
b.r = l
b.y = l
h.t = j
h.z = m
h.r = n
h.p = n
h.y = k
h.s = f
m.t = j
m.z = e
m.r = n
m.p = n
m.y = k
m.s = f
assert l.y.t.r.p.u.y.w.txt == "
class A:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: D = None
        self.o: F = None
        self.t: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: D = None
        self.y: D = None
        self.txt = txt

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

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

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

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