class A:
    def __init__(self, txt: str):
        self.q: D = None
        self.z: C = None
        self.v: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: I = None
        self.z: H = None
        self.q: B = None
        self.r: H = None
        self.u: A = None
        self.x: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: F = None
        self.p: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.z: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: H = None
        self.u: A = None
        self.s: H = None
        self.w: D = None
        self.t: E = None
        self.x: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: I = None
        self.z: H = None
        self.q: B = None
        self.r: H = None
        self.u: A = None
        self.x: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: F = None
        self.p: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: C = None
        self.z: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: B = None
        self.y: H = None
        self.u: A = None
        self.s: H = None
        self.w: D = None
        self.t: E = None
        self.x: C = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

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

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