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

class B:
    def __init__(self, txt: str):
        self.s: H = None
        self.t: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.r: G = None
        self.w: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.r: C = None
        self.p: I = None
        self.y: J = None
        self.s: J = None
        self.q: B = None
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.u: E = None
        self.o: J = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.x: A = None
        self.u: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: H = None
        self.t: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.r: G = None
        self.w: H = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.r: C = None
        self.p: I = None
        self.y: J = None
        self.s: J = None
        self.q: B = None
        self.t: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.u: E = None
        self.o: J = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.x: A = None
        self.u: H = None
        self.txt = txt

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

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