class A:
    def __init__(self, txt: str):
        self.t: D = None
        self.q: F = None
        self.y: J = None
        self.x: G = None
        self.o: I = None
        self.v: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: I = None
        self.r: J = None
        self.t: I = None
        self.y: G = None
        self.s: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: H = None
        self.z: G = None
        self.s: I = None
        self.p: E = None
        self.v: J = None
        self.r: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: D = None
        self.o: J = None
        self.r: D = None
        self.s: B = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: D = None
        self.x: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.o: A = None
        self.z: D = None
        self.r: H = None
        self.t: B = None
        self.v: F = None
        self.x: G = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: I = None
        self.r: J = None
        self.t: I = None
        self.y: G = None
        self.s: I = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: H = None
        self.z: G = None
        self.s: I = None
        self.p: E = None
        self.v: J = None
        self.r: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: D = None
        self.o: J = None
        self.r: D = None
        self.s: B = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: D = None
        self.x: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.o: A = None
        self.z: D = None
        self.r: H = None
        self.t: B = None
        self.v: F = None
        self.x: G = None
        self.txt = txt

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

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

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