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

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.x: F = None
        self.r: I = None
        self.z: H = None
        self.u: A = None
        self.t: H = None
        self.v: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: H = None
        self.z: F = None
        self.x: B = None
        self.o: E = None
        self.t: A = None
        self.q: H = None
        self.s: A = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: I = None
        self.x: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.x: F = None
        self.r: I = None
        self.z: H = None
        self.u: A = None
        self.t: H = None
        self.v: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: H = None
        self.z: F = None
        self.x: B = None
        self.o: E = None
        self.t: A = None
        self.q: H = None
        self.s: A = None
        self.v: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: A = None
        self.s: I = None
        self.x: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

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

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