class A:
    def __init__(self, txt: str):
        self.u: G = None
        self.s: I = None
        self.y: D = None
        self.o: J = None
        self.x: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.u: D = None
        self.s: J = None
        self.q: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.z: F = None
        self.s: J = None
        self.r: G = None
        self.q: I = None
        self.x: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: C = None
        self.z: A = None
        self.v: E = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: I = None
        self.t: E = None
        self.r: C = None
        self.y: E = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.u: D = None
        self.s: J = None
        self.q: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.z: F = None
        self.s: J = None
        self.r: G = None
        self.q: I = None
        self.x: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: C = None
        self.z: A = None
        self.v: E = None
        self.x: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: I = None
        self.t: E = None
        self.r: C = None
        self.y: E = None
        self.txt = txt

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

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

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

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

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