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

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

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.x: J = None
        self.q: D = None
        self.r: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.z: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: E = None
        self.w: H = None
        self.z: A = None
        self.t: A = None
        self.o: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: I = None
        self.x: J = None
        self.q: D = None
        self.r: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.z: A = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.q: E = None
        self.w: H = None
        self.z: A = None
        self.t: A = None
        self.o: D = None
        self.txt = txt

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

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