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

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

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

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.s: B = None
        self.r: F = None
        self.y: B = None
        self.o: D = None
        self.t: B = None
        self.txt = txt

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: B = None
        self.s: B = None
        self.r: F = None
        self.y: B = None
        self.o: D = None
        self.t: B = None
        self.txt = txt

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

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

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

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