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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.q: A = None
        self.x: D = None
        self.t: F = None
        self.r: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.p: B = None
        self.q: H = None
        self.x: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: A = None
        self.z: J = None
        self.w: H = None
        self.o: H = None
        self.x: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: D = None
        self.t: J = None
        self.x: B = None
        self.v: C = None
        self.z: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: H = None
        self.s: J = None
        self.x: C = None
        self.v: E = None
        self.o: A = None
        self.w: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.q: A = None
        self.x: D = None
        self.t: F = None
        self.r: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: B = None
        self.p: B = None
        self.q: H = None
        self.x: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: A = None
        self.z: J = None
        self.w: H = None
        self.o: H = None
        self.x: A = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: A = None
        self.o: D = None
        self.t: J = None
        self.x: B = None
        self.v: C = None
        self.z: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: H = None
        self.s: J = None
        self.x: C = None
        self.v: E = None
        self.o: A = None
        self.w: D = None
        self.txt = txt

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

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

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