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

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

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

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

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: J = None
        self.v: J = None
        self.r: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: A = None
        self.r: B = None
        self.y: C = None
        self.x: E = None
        self.o: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: B = None
        self.w: J = None
        self.v: B = None
        self.p: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: H = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: J = None
        self.v: J = None
        self.r: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: A = None
        self.r: B = None
        self.y: C = None
        self.x: E = None
        self.o: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: B = None
        self.w: J = None
        self.v: B = None
        self.p: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: H = None
        self.txt = txt

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

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

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