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

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

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

class D:
    def __init__(self, txt: str):
        self.p: I = None
        self.o: H = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.z: C = None
        self.v: D = None
        self.y: B = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: I = None
        self.o: H = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.z: C = None
        self.v: D = None
        self.y: B = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

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

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