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

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.q: B = None
        self.r: B = None
        self.v: J = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: F = None
        self.y: C = None
        self.x: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: G = None
        self.u: E = None
        self.r: G = None
        self.p: D = None
        self.s: B = None
        self.z: E = None
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: D = None
        self.z: D = None
        self.w: H = None
        self.v: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: A = None
        self.q: J = None
        self.u: C = None
        self.p: C = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.q: B = None
        self.r: B = None
        self.v: J = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: F = None
        self.y: C = None
        self.x: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: G = None
        self.u: E = None
        self.r: G = None
        self.p: D = None
        self.s: B = None
        self.z: E = None
        self.y: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: D = None
        self.z: D = None
        self.w: H = None
        self.v: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: A = None
        self.q: J = None
        self.u: C = None
        self.p: C = None
        self.txt = txt

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

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

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