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

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.z: C = None
        self.x: D = None
        self.p: J = None
        self.o: D = None
        self.u: G = None
        self.s: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: J = None
        self.s: E = None
        self.x: F = None
        self.w: C = None
        self.o: J = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: J = None
        self.x: C = None
        self.t: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.v: I = None
        self.q: D = None
        self.z: I = None
        self.x: F = None
        self.p: J = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.z: C = None
        self.x: D = None
        self.p: J = None
        self.o: D = None
        self.u: G = None
        self.s: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: J = None
        self.s: E = None
        self.x: F = None
        self.w: C = None
        self.o: J = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.s: J = None
        self.x: C = None
        self.t: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.v: I = None
        self.q: D = None
        self.z: I = None
        self.x: F = None
        self.p: J = None
        self.txt = txt

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

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

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

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