class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.o: C = None
        self.p: C = None
        self.q: E = None
        self.t: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: F = None
        self.p: E = None
        self.x: C = None
        self.q: C = None
        self.v: C = None
        self.y: A = None
        self.t: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.u: G = None
        self.y: C = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.s: D = None
        self.x: G = None
        self.u: A = None
        self.o: F = None
        self.r: D = None
        self.z: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: H = None
        self.x: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: H = None
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: G = None
        self.u: E = None
        self.r: C = None
        self.t: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: D = None
        self.o: F = None
        self.p: E = None
        self.x: C = None
        self.q: C = None
        self.v: C = None
        self.y: A = None
        self.t: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.u: G = None
        self.y: C = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: H = None
        self.s: D = None
        self.x: G = None
        self.u: A = None
        self.o: F = None
        self.r: D = None
        self.z: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: H = None
        self.x: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: H = None
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: E = None
        self.v: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: G = None
        self.u: E = None
        self.r: C = None
        self.t: B = None
        self.txt = txt

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

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