class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.r: I = None
        self.txt = txt

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.w: C = None
        self.r: B = None
        self.q: C = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.w: C = None
        self.r: B = None
        self.q: C = None
        self.txt = txt

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

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

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

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