class A:
    def __init__(self, txt: str):
        self.o: D = None
        self.v: E = None
        self.u: E = None
        self.s: D = None
        self.w: G = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: H = None
        self.t: F = None
        self.z: B = None
        self.w: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: J = None
        self.s: E = None
        self.z: G = None
        self.u: C = None
        self.t: A = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: A = None
        self.r: E = None
        self.t: D = None
        self.p: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: A = None
        self.w: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: A = None
        self.z: C = None
        self.r: E = None
        self.p: E = None
        self.u: A = None
        self.w: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: H = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.y: H = None
        self.t: F = None
        self.z: B = None
        self.w: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: J = None
        self.s: E = None
        self.z: G = None
        self.u: C = None
        self.t: A = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: A = None
        self.r: E = None
        self.t: D = None
        self.p: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: A = None
        self.w: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.y: A = None
        self.z: C = None
        self.r: E = None
        self.p: E = None
        self.u: A = None
        self.w: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: H = None
        self.txt = txt

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

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