class A:
    def __init__(self, txt: str):
        self.v: C = None
        self.y: G = None
        self.x: J = None
        self.w: C = None
        self.p: I = None
        self.s: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: A = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: H = None
        self.t: H = None
        self.y: A = None
        self.r: D = None
        self.v: J = None
        self.z: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.t: F = None
        self.w: I = None
        self.r: E = None
        self.u: E = None
        self.z: E = None
        self.v: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.o: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.q: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: A = None
        self.r: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: H = None
        self.t: H = None
        self.y: A = None
        self.r: D = None
        self.v: J = None
        self.z: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.o: G = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.t: F = None
        self.w: I = None
        self.r: E = None
        self.u: E = None
        self.z: E = None
        self.v: F = None
        self.txt = txt

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

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