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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: F = None
        self.q: G = None
        self.s: E = None
        self.o: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.w: J = None
        self.x: F = None
        self.q: C = None
        self.o: H = None
        self.s: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.u: C = None
        self.p: E = None
        self.x: F = None
        self.z: J = None
        self.s: I = None
        self.w: E = None
        self.y: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.x: E = None
        self.v: C = None
        self.q: F = None
        self.w: J = None
        self.p: C = None
        self.r: E = None
        self.y: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: D = None
        self.z: B = None
        self.v: J = None
        self.u: A = None
        self.t: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: C = None
        self.p: C = None
        self.z: D = None
        self.txt = txt

f = A("f")
k = B("k")
a = C("a")
m = D("m")
b = E("b")
d = F("d")
n = G("n")
h = H("h")
c = I("c")
l = J("l")

f.v = m
f.x = d
f.u = d
f.y = c
f.w = n
f.q = l
k.u = d
k.z = d
k.q = n
k.o = n
k.s = b
a.u = f
a.t = c
a.r = c
a.p = n
a.z = n
a.s = k
a.v = k
a.y = b
a.o = d
a.w = m
m.y = k
m.w = l
m.x = d
m.q = a
m.o = h
m.s = b
b.y = d
b.x = c
b.o = c
b.v = n
b.z = l
b.p = l
b.s = h
b.q = f
d.x = k
d.w = k
d.v = b
d.p = a
d.s = a
d.z = h
d.t = h
d.u = n
d.o = l
d.y = l
n.u = a
n.p = b
n.w = b
n.x = d
n.z = l
n.s = c
n.y = k
h.o = f
h.x = b
h.r = b
h.v = a
h.p = a
h.q = d
h.w = l
h.y = c
c.w = m
c.z = k
c.v = l
c.t = l
c.u = f
l.x = b
l.t = a
l.p = a
l.z = m
assert h.o.q.z.q.v.u.o.z.s.txt == "
class A:
    def __init__(self, txt: str):
        self.v: D = None
        self.x: F = None
        self.y: I = None
        self.w: G = None
        self.u: F = None
        self.q: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: F = None
        self.q: G = None
        self.s: E = None
        self.o: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: B = None
        self.w: J = None
        self.x: F = None
        self.q: C = None
        self.o: H = None
        self.s: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.u: C = None
        self.p: E = None
        self.x: F = None
        self.z: J = None
        self.s: I = None
        self.w: E = None
        self.y: B = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.x: E = None
        self.v: C = None
        self.q: F = None
        self.w: J = None
        self.p: C = None
        self.r: E = None
        self.y: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: D = None
        self.z: B = None
        self.v: J = None
        self.u: A = None
        self.t: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: C = None
        self.p: C = None
        self.z: D = None
        self.txt = txt

f = A("f")
k = B("k")
a = C("a")
m = D("m")
b = E("b")
d = F("d")
n = G("n")
h = H("h")
c = I("c")
l = J("l")

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