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

class B:
    def __init__(self, txt: str):
        self.q: J = None
        self.y: F = None
        self.w: E = None
        self.s: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.q: J = None
        self.u: A = None
        self.r: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: A = None
        self.r: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: D = None
        self.q: G = None
        self.u: G = None
        self.t: E = None
        self.x: G = None
        self.v: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: J = None
        self.y: F = None
        self.w: E = None
        self.s: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.t: A = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: I = None
        self.q: J = None
        self.u: A = None
        self.r: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: A = None
        self.r: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: A = None
        self.p: D = None
        self.q: G = None
        self.u: G = None
        self.t: E = None
        self.x: G = None
        self.v: G = None
        self.txt = txt

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

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