class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: A = None
        self.q: E = None
        self.z: F = None
        self.o: D = None
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.z: D = None
        self.u: C = None
        self.y: E = None
        self.q: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.s: B = None
        self.z: E = None
        self.o: E = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.z: D = None
        self.u: C = None
        self.y: E = None
        self.q: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.s: B = None
        self.z: E = None
        self.o: E = None
        self.txt = txt

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

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

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

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

b.v = f
b.y = m
b.q = n
b.z = g
b.o = i
b.x = e
h.r = f
h.u = f
h.z = i
h.y = n
h.q = g
f.y = j
f.s = j
f.z = n
f.o = n
i.w = f
i.t = f
i.y = f
i.v = j
i.z = n
n.s = j
n.t = g
n.u = i
g.v = e
g.q = e
g.w = i
g.p = i
g.o = j
m.v = f
m.y = b
m.q = n
m.z = e
m.x = e
m.o = i
j.r = f
j.u = f
j.z = i
j.y = n
j.q = g
e.v = g
e.q = g
e.w = i
e.p = i
e.o = j
assert e.q.o.z.y.txt == "f"