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

class B:
    def __init__(self, txt: str):
        self.z: F = None
        self.x: G = None
        self.v: D = None
        self.r: D = None
        self.s: D = None
        self.w: C = None
        self.t: I = None
        self.u: I = None
        self.o: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.w: F = None
        self.p: D = None
        self.s: E = None
        self.o: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: I = None
        self.y: G = None
        self.o: E = None
        self.w: B = None
        self.p: A = None
        self.z: I = None
        self.s: A = None
        self.t: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.p: F = None
        self.y: C = None
        self.w: H = None
        self.t: C = None
        self.r: I = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: A = None
        self.p: I = None
        self.q: F = None
        self.x: D = None
        self.v: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: B = None
        self.y: G = None
        self.q: C = None
        self.z: F = None
        self.v: H = None
        self.s: G = None
        self.r: A = None
        self.txt = txt

j = A("j")
f = B("f")
i = C("i")
e = D("e")
d = E("d")
h = F("h")
l = G("l")
b = H("b")
k = I("k")
m = I("m")

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

class B:
    def __init__(self, txt: str):
        self.z: F = None
        self.x: G = None
        self.v: D = None
        self.r: D = None
        self.s: D = None
        self.w: C = None
        self.t: I = None
        self.u: I = None
        self.o: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.w: F = None
        self.p: D = None
        self.s: E = None
        self.o: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: I = None
        self.y: G = None
        self.o: E = None
        self.w: B = None
        self.p: A = None
        self.z: I = None
        self.s: A = None
        self.t: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.p: F = None
        self.y: C = None
        self.w: H = None
        self.t: C = None
        self.r: I = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: A = None
        self.p: I = None
        self.q: F = None
        self.x: D = None
        self.v: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: B = None
        self.y: G = None
        self.q: C = None
        self.z: F = None
        self.v: H = None
        self.s: G = None
        self.r: A = None
        self.txt = txt

j = A("j")
f = B("f")
i = C("i")
e = D("e")
d = E("d")
h = F("h")
l = G("l")
b = H("b")
k = I("k")
m = I("m")

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