class A:
    def __init__(self, txt: str):
        self.v: H = None
        self.p: G = None
        self.y: B = None
        self.o: I = None
        self.u: J = None
        self.w: H = None
        self.t: I = None
        self.z: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.u: D = None
        self.o: F = None
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: F = None
        self.t: J = None
        self.r: F = None
        self.s: J = None
        self.p: C = None
        self.u: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.u: D = None
        self.z: J = None
        self.x: B = None
        self.s: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: A = None
        self.t: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: G = None
        self.u: D = None
        self.o: F = None
        self.s: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.z: F = None
        self.t: J = None
        self.r: F = None
        self.s: J = None
        self.p: C = None
        self.u: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.u: D = None
        self.z: J = None
        self.x: B = None
        self.s: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.o: A = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: A = None
        self.t: A = None
        self.txt = txt

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

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