class A:
    def __init__(self, txt: str):
        self.z: B = None
        self.w: B = None
        self.v: F = None
        self.o: D = None
        self.p: D = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: D = None
        self.txt = txt

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

k.z = j
k.w = g
k.v = b
k.o = i
k.p = i
j.w = c
j.v = b
j.z = g
a.v = j
a.q = i
a.t = i
a.z = g
a.w = c
a.p = k
i.o = c
i.p = l
i.v = b
h.t = e
b.z = i
l.o = a
l.p = i
l.v = b
e.z = g
e.w = g
e.v = b
e.o = l
e.p = i
g.w = c
g.v = b
g.z = j
c.v = g
c.z = g
c.q = i
c.t = i
c.w = a
c.p = e
assert h.t.p.p.v.txt == "b"