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

class B:
    def __init__(self, txt: str):
        self.p: F = None
        self.x: A = None
        self.o: H = None
        self.t: C = None
        self.s: C = None
        self.z: H = None
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: F = None
        self.r: G = None
        self.t: H = None
        self.v: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: D = None
        self.r: D = None
        self.o: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: F = None
        self.u: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: H = None
        self.r: C = None
        self.u: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.p: F = None
        self.x: A = None
        self.o: H = None
        self.t: C = None
        self.s: C = None
        self.z: H = None
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: F = None
        self.u: F = None
        self.r: G = None
        self.t: H = None
        self.v: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: E = None
        self.q: D = None
        self.r: D = None
        self.o: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: F = None
        self.u: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: H = None
        self.r: C = None
        self.u: B = None
        self.txt = txt

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

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