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

class B:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: D = None
        self.o: A = None
        self.x: J = None
        self.p: A = None
        self.txt = txt

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

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

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.t: D = None
        self.o: A = None
        self.x: J = None
        self.p: A = None
        self.txt = txt

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

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

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

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

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

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

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