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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.p: C = None
        self.u: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: E = None
        self.s: H = None
        self.p: E = None
        self.r: A = None
        self.w: G = None
        self.o: G = None
        self.z: E = None
        self.txt = txt

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

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.s: H = None
        self.p: C = None
        self.u: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.t: E = None
        self.s: H = None
        self.p: E = None
        self.r: A = None
        self.w: G = None
        self.o: G = None
        self.z: E = None
        self.txt = txt

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

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

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