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

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

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

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.r: G = None
        self.t: E = None
        self.y: E = None
        self.q: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.q: F = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: J = None
        self.u: F = None
        self.r: F = None
        self.q: E = None
        self.z: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: H = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.s: I = None
        self.r: G = None
        self.t: E = None
        self.y: E = None
        self.q: G = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.q: F = None
        self.u: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: J = None
        self.u: F = None
        self.r: F = None
        self.q: E = None
        self.z: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.x: H = None
        self.txt = txt

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

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

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