class A:
    def __init__(self, txt: str):
        self.w: G = None
        self.q: B = None
        self.o: I = None
        self.y: G = None
        self.v: E = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.u: G = None
        self.q: J = None
        self.s: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: I = None
        self.z: B = None
        self.u: I = None
        self.p: A = None
        self.s: C = None
        self.txt = txt

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

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

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

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

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: A = None
        self.u: G = None
        self.q: J = None
        self.s: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: I = None
        self.z: B = None
        self.u: I = None
        self.p: A = None
        self.s: C = None
        self.txt = txt

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

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

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

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

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