class A:
    def __init__(self, txt: str):
        self.y: J = None
        self.r: E = None
        self.u: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.o: E = None
        self.x: I = None
        self.r: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.o: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.u: H = None
        self.v: H = None
        self.w: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: G = None
        self.u: G = None
        self.x: F = None
        self.r: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: E = None
        self.o: E = None
        self.x: I = None
        self.r: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.o: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: F = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.p: E = None
        self.u: H = None
        self.v: H = None
        self.w: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.w: F = None
        self.p: G = None
        self.u: G = None
        self.x: F = None
        self.r: F = None
        self.txt = txt

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

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

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