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

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: I = None
        self.w: G = None
        self.z: J = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: I = None
        self.p: J = None
        self.q: A = None
        self.s: J = None
        self.u: B = None
        self.r: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: J = None
        self.s: I = None
        self.w: F = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: I = None
        self.w: G = None
        self.z: J = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.y: I = None
        self.p: J = None
        self.q: A = None
        self.s: J = None
        self.u: B = None
        self.r: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: J = None
        self.s: I = None
        self.w: F = None
        self.txt = txt

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

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

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

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

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