class A:
    def __init__(self, txt: str):
        self.u: C = None
        self.s: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: A = None
        self.s: H = None
        self.o: H = None
        self.x: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: B = None
        self.r: E = None
        self.x: A = None
        self.p: I = None
        self.y: H = None
        self.w: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.r: A = None
        self.x: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.x: H = None
        self.r: B = None
        self.s: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: E = None
        self.o: E = None
        self.x: C = None
        self.r: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: E = None
        self.s: A = None
        self.y: H = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: F = None
        self.w: A = None
        self.s: H = None
        self.o: H = None
        self.x: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: B = None
        self.r: E = None
        self.x: A = None
        self.p: I = None
        self.y: H = None
        self.w: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: H = None
        self.r: A = None
        self.x: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.x: H = None
        self.r: B = None
        self.s: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: E = None
        self.o: E = None
        self.x: C = None
        self.r: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.t: A = None
        self.x: E = None
        self.s: A = None
        self.y: H = None
        self.txt = txt

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

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

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