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

class B:
    def __init__(self, txt: str):
        self.p: D = None
        self.v: I = None
        self.y: J = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: E = None
        self.t: H = None
        self.z: J = None
        self.u: E = None
        self.p: E = None
        self.w: H = None
        self.v: C = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.u: A = None
        self.r: A = None
        self.w: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: G = None
        self.t: J = None
        self.x: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: J = None
        self.u: J = None
        self.z: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: D = None
        self.v: I = None
        self.y: J = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: E = None
        self.t: H = None
        self.z: J = None
        self.u: E = None
        self.p: E = None
        self.w: H = None
        self.v: C = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.u: A = None
        self.r: A = None
        self.w: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.q: G = None
        self.t: J = None
        self.x: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: J = None
        self.u: J = None
        self.z: F = None
        self.txt = txt

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

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

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