class A:
    def __init__(self, txt: str):
        self.o: I = None
        self.q: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: C = None
        self.y: F = None
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.r: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: A = None
        self.v: E = None
        self.q: H = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: C = None
        self.y: F = None
        self.u: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.r: B = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.x: A = None
        self.v: E = None
        self.q: H = None
        self.txt = txt

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

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

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

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

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