class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.v: F = None
        self.s: F = None
        self.x: D = None
        self.p: D = None
        self.txt = txt

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

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

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

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

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

i = A("i")
j = B("j")
h = C("h")
e = D("e")
c = E("c")
n = F("n")
b = B("b")
a = E("a")
g = E("g")
l = D("l")

i.z = l
i.x = l
i.p = l
i.v = n
i.s = n
j.o = b
j.z = n
j.t = a
j.u = e
h.q = i
e.s = l
e.r = n
e.t = n
c.w = i
c.r = h
n.w = c
n.t = a
n.u = a
b.o = j
b.z = n
b.t = c
b.u = e
a.w = i
a.r = h
g.w = i
g.r = h
l.s = e
l.r = n
l.t = n
assert h.q.s.u.w.s.w.r.q.v.txt == "
class A:
    def __init__(self, txt: str):
        self.z: D = None
        self.v: F = None
        self.s: F = None
        self.x: D = None
        self.p: D = None
        self.txt = txt

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

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

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

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

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

i = A("i")
j = B("j")
h = C("h")
e = D("e")
c = E("c")
n = F("n")
b = B("b")
a = E("a")
g = E("g")
l = D("l")

i.z = l
i.x = l
i.p = l
i.v = n
i.s = n
j.o = b
j.z = n
j.t = a
j.u = e
h.q = i
e.s = l
e.r = n
e.t = n
c.w = i
c.r = h
n.w = c
n.t = a
n.u = a
b.o = j
b.z = n
b.t = c
b.u = e
a.w = i
a.r = h
g.w = i
g.r = h
l.s = e
l.r = n
l.t = n
assert h.q.s.u.w.s.w.r.q.v.txt == "n"