class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.x: G = None
        self.q: B = None
        self.u: G = None
        self.p: C = None
        self.s: H = None
        self.t: I = None
        self.o: B = None
        self.txt = txt

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.v: D = None
        self.x: F = None
        self.w: I = None
        self.q: I = None
        self.u: B = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.v: D = None
        self.x: F = None
        self.w: I = None
        self.q: I = None
        self.u: B = None
        self.txt = txt

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

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

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

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