class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.w: I = None
        self.z: C = None
        self.x: D = None
        self.u: I = None
        self.v: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.z: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.p: F = None
        self.t: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.w: E = None
        self.o: E = None
        self.s: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.s: C = None
        self.z: J = None
        self.x: E = None
        self.p: E = None
        self.t: C = None
        self.o: J = None
        self.u: E = None
        self.v: J = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: J = None
        self.p: F = None
        self.t: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: F = None
        self.w: E = None
        self.o: E = None
        self.s: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: G = None
        self.s: C = None
        self.z: J = None
        self.x: E = None
        self.p: E = None
        self.t: C = None
        self.o: J = None
        self.u: E = None
        self.v: J = None
        self.txt = txt

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

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

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

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