class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.p: F = None
        self.v: B = None
        self.o: I = None
        self.z: B = None
        self.q: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.t: C = None
        self.q: D = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: F = None
        self.x: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: I = None
        self.q: E = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: D = None
        self.x: J = None
        self.w: J = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: I = None
        self.t: C = None
        self.q: D = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: F = None
        self.x: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: A = None
        self.u: I = None
        self.q: E = None
        self.o: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: D = None
        self.x: J = None
        self.w: J = None
        self.txt = txt

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

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

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

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