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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: B = None
        self.v: J = None
        self.t: E = None
        self.u: I = None
        self.r: E = None
        self.s: I = None
        self.y: J = None
        self.z: J = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: F = None
        self.txt = txt

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

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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.q: H = None
        self.o: B = None
        self.v: J = None
        self.t: E = None
        self.u: I = None
        self.r: E = None
        self.s: I = None
        self.y: J = None
        self.z: J = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.x: G = None
        self.o: F = None
        self.txt = txt

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

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