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

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.t: C = None
        self.o: C = None
        self.z: E = None
        self.w: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.p: C = None
        self.r: G = None
        self.y: B = None
        self.u: D = None
        self.w: A = None
        self.z: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: B = None
        self.u: E = None
        self.txt = txt

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

e.o = d
e.q = j
e.u = j
e.v = j
e.y = k
e.r = k
e.p = m
e.s = n
e.t = b
e.x = b
m.z = n
i.y = k
i.x = d
i.v = m
i.u = m
i.s = m
i.z = n
i.o = f
k.r = n
k.u = m
k.y = d
k.t = d
k.w = b
k.q = b
k.s = b
k.z = e
k.v = i
d.v = j
d.u = g
d.y = g
d.w = g
d.r = k
d.s = i
d.q = f
b.x = j
b.q = g
b.z = g
b.r = i
b.p = k
b.v = k
b.o = n
b.w = n
f.t = i
f.o = i
f.z = d
f.w = e
g.w = j
g.z = j
g.x = j
g.s = i
g.o = i
g.t = i
g.v = b
g.r = n
g.u = d
g.q = m
j.q = e
j.w = e
j.p = i
j.r = f
j.y = m
j.u = k
j.z = k
n.o = m
n.u = d
assert i.y.t.r.y.y.u.v.z.s.txt == "
class A:
    def __init__(self, txt: str):
        self.o: E = None
        self.q: I = None
        self.y: D = None
        self.p: B = None
        self.r: D = None
        self.s: J = None
        self.t: F = None
        self.x: F = None
        self.u: I = None
        self.v: I = None
        self.txt = txt

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

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

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

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

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

class G:
    def __init__(self, txt: str):
        self.t: C = None
        self.o: C = None
        self.z: E = None
        self.w: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.p: C = None
        self.r: G = None
        self.y: B = None
        self.u: D = None
        self.w: A = None
        self.z: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: B = None
        self.u: E = None
        self.txt = txt

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

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