class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.p: F = None
        self.v: C = None
        self.w: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.y: F = None
        self.v: H = None
        self.t: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.r: G = None
        self.q: B = None
        self.v: A = None
        self.t: H = None
        self.w: I = None
        self.u: F = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.s: I = None
        self.w: A = None
        self.y: E = None
        self.v: G = None
        self.z: A = None
        self.u: D = None
        self.q: I = None
        self.x: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: B = None
        self.s: E = None
        self.u: F = None
        self.w: D = None
        self.y: H = None
        self.t: H = None
        self.q: F = None
        self.z: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: H = None
        self.q: C = None
        self.s: C = None
        self.u: A = None
        self.o: H = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: D = None
        self.y: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: C = None
        self.y: F = None
        self.v: H = None
        self.t: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.r: G = None
        self.q: B = None
        self.v: A = None
        self.t: H = None
        self.w: I = None
        self.u: F = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: A = None
        self.s: I = None
        self.w: A = None
        self.y: E = None
        self.v: G = None
        self.z: A = None
        self.u: D = None
        self.q: I = None
        self.x: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: B = None
        self.s: E = None
        self.u: F = None
        self.w: D = None
        self.y: H = None
        self.t: H = None
        self.q: F = None
        self.z: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: H = None
        self.q: C = None
        self.s: C = None
        self.u: A = None
        self.o: H = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: D = None
        self.y: D = None
        self.txt = txt

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

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