class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: H = None
        self.t: G = None
        self.r: A = None
        self.w: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: F = None
        self.y: C = None
        self.p: J = None
        self.x: C = None
        self.txt = txt

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

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

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

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

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

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

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

g.x = h
i.o = b
i.t = l
i.r = g
i.w = j
c.x = g
e.z = h
e.y = c
e.x = c
e.p = j
f.z = e
h.t = b
h.w = b
h.p = g
h.v = f
h.s = i
l.v = b
b.q = f
b.w = f
b.x = f
b.r = j
b.v = e
b.s = i
b.t = i
b.y = i
b.z = a
a.s = l
a.w = h
j.w = h
j.s = h
j.r = a
j.v = a
j.t = l
j.o = c
j.y = c
assert l.v.t.o.z.s.v.txt == "
class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: H = None
        self.t: G = None
        self.r: A = None
        self.w: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: F = None
        self.y: C = None
        self.p: J = None
        self.x: C = None
        self.txt = txt

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

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

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

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

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

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

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

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