class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: E = None
        self.v: I = None
        self.w: I = None
        self.q: I = None
        self.u: C = None
        self.z: E = None
        self.o: C = None
        self.r: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: J = None
        self.w: I = None
        self.v: E = None
        self.q: H = None
        self.u: E = None
        self.o: H = None
        self.z: C = None
        self.x: J = None
        self.y: G = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: A = None
        self.w: A = None
        self.q: I = None
        self.v: J = None
        self.o: D = None
        self.u: A = None
        self.p: G = None
        self.z: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.u: C = None
        self.s: A = None
        self.y: D = None
        self.t: E = None
        self.o: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: H = None
        self.q: F = None
        self.v: G = None
        self.u: G = None
        self.o: G = None
        self.r: D = None
        self.y: C = None
        self.txt = txt

e = A("e")
b = B("b")
c = C("c")
m = D("m")
a = E("a")
l = F("l")
g = G("g")
n = H("n")
f = I("f")
k = J("k")

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

class B:
    def __init__(self, txt: str):
        self.p: E = None
        self.v: I = None
        self.w: I = None
        self.q: I = None
        self.u: C = None
        self.z: E = None
        self.o: C = None
        self.r: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.r: J = None
        self.w: I = None
        self.v: E = None
        self.q: H = None
        self.u: E = None
        self.o: H = None
        self.z: C = None
        self.x: J = None
        self.y: G = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: A = None
        self.w: A = None
        self.q: I = None
        self.v: J = None
        self.o: D = None
        self.u: A = None
        self.p: G = None
        self.z: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: D = None
        self.u: C = None
        self.s: A = None
        self.y: D = None
        self.t: E = None
        self.o: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: A = None
        self.s: H = None
        self.q: F = None
        self.v: G = None
        self.u: G = None
        self.o: G = None
        self.r: D = None
        self.y: C = None
        self.txt = txt

e = A("e")
b = B("b")
c = C("c")
m = D("m")
a = E("a")
l = F("l")
g = G("g")
n = H("n")
f = I("f")
k = J("k")

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