class A:
    def __init__(self, txt: str):
        self.v: H = None
        self.r: H = None
        self.u: G = None
        self.y: D = None
        self.w: I = None
        self.s: C = None
        self.x: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.u: F = None
        self.z: G = None
        self.v: F = None
        self.y: E = None
        self.o: G = None
        self.t: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.s: H = None
        self.t: G = None
        self.z: F = None
        self.q: H = None
        self.x: E = None
        self.w: G = None
        self.u: G = None
        self.p: H = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.u: F = None
        self.z: G = None
        self.v: F = None
        self.y: E = None
        self.o: G = None
        self.t: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: G = None
        self.s: H = None
        self.t: G = None
        self.z: F = None
        self.q: H = None
        self.x: E = None
        self.w: G = None
        self.u: G = None
        self.p: H = None
        self.txt = txt

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

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