class A:
    def __init__(self, txt: str):
        self.s: B = None
        self.q: D = None
        self.p: H = None
        self.v: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.p: I = None
        self.q: F = None
        self.y: H = None
        self.s: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: H = None
        self.y: A = None
        self.q: A = None
        self.w: E = None
        self.t: I = None
        self.u: I = None
        self.v: B = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: H = None
        self.y: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: J = None
        self.t: I = None
        self.s: E = None
        self.p: B = None
        self.y: J = None
        self.q: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.u: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: J = None
        self.q: D = None
        self.s: A = None
        self.r: C = None
        self.p: F = None
        self.t: B = None
        self.x: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: F = None
        self.z: G = None
        self.t: E = None
        self.x: B = None
        self.o: J = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.p: I = None
        self.q: F = None
        self.y: H = None
        self.s: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: H = None
        self.y: A = None
        self.q: A = None
        self.w: E = None
        self.t: I = None
        self.u: I = None
        self.v: B = None
        self.p: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: H = None
        self.y: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: J = None
        self.t: I = None
        self.s: E = None
        self.p: B = None
        self.y: J = None
        self.q: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.u: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.y: J = None
        self.q: D = None
        self.s: A = None
        self.r: C = None
        self.p: F = None
        self.t: B = None
        self.x: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: F = None
        self.z: G = None
        self.t: E = None
        self.x: B = None
        self.o: J = None
        self.txt = txt

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

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

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