class A:
    def __init__(self, txt: str):
        self.o: I = None
        self.q: B = None
        self.u: D = None
        self.x: H = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: F = None
        self.t: B = None
        self.q: G = None
        self.txt = txt

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

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.q: C = None
        self.p: F = None
        self.x: B = None
        self.s: B = None
        self.u: D = None
        self.z: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: F = None
        self.t: B = None
        self.q: G = None
        self.txt = txt

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

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.q: C = None
        self.p: F = None
        self.x: B = None
        self.s: B = None
        self.u: D = None
        self.z: B = None
        self.txt = txt

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

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