class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.r: B = None
        self.u: B = None
        self.s: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.z: E = None
        self.t: A = None
        self.p: B = None
        self.v: F = None
        self.s: C = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: E = None
        self.v: D = None
        self.q: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.w: C = None
        self.v: G = None
        self.p: C = None
        self.y: D = None
        self.o: J = None
        self.q: J = None
        self.t: I = None
        self.x: F = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: E = None
        self.z: E = None
        self.t: A = None
        self.p: B = None
        self.v: F = None
        self.s: C = None
        self.o: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: E = None
        self.v: D = None
        self.q: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.w: C = None
        self.v: G = None
        self.p: C = None
        self.y: D = None
        self.o: J = None
        self.q: J = None
        self.t: I = None
        self.x: F = None
        self.txt = txt

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

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

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

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