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

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

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: I = None
        self.p: H = None
        self.t: B = None
        self.r: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: C = None
        self.y: B = None
        self.u: I = None
        self.x: F = None
        self.o: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: B = None
        self.p: D = None
        self.o: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: I = None
        self.p: H = None
        self.t: B = None
        self.r: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.w: H = None
        self.r: C = None
        self.y: B = None
        self.u: I = None
        self.x: F = None
        self.o: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: B = None
        self.p: D = None
        self.o: B = None
        self.txt = txt

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

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