class A:
    def __init__(self, txt: str):
        self.o: E = None
        self.s: F = None
        self.v: H = None
        self.r: I = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.x: A = None
        self.s: H = None
        self.z: F = None
        self.t: B = None
        self.r: B = None
        self.p: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: A = None
        self.y: G = None
        self.x: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: F = None
        self.t: I = None
        self.y: B = None
        self.u: I = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.x: A = None
        self.s: H = None
        self.z: F = None
        self.t: B = None
        self.r: B = None
        self.p: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: A = None
        self.y: G = None
        self.x: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: F = None
        self.t: I = None
        self.y: B = None
        self.u: I = None
        self.txt = txt

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

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

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

h.o = f
h.s = c
h.v = b
h.r = a
k.y = a
k.t = m
k.v = m
k.u = f
k.o = d
k.p = h
m.w = f
m.x = h
m.p = h
m.s = b
m.z = c
m.t = k
m.r = k
n.u = d
n.z = b
n.s = m
f.p = k
f.t = h
f.x = h
f.y = d
c.t = f
c.y = h
c.q = b
c.v = a
d.p = c
d.t = a
d.u = a
d.y = k
b.v = f
b.r = f
b.z = d
b.p = d
b.y = d
b.x = c
b.w = c
b.q = m
b.u = h
a.y = m
a.q = f
assert n.u.u.y.w.t.s.txt == "c"