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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: B = None
        self.x: B = None
        self.z: D = None
        self.v: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: J = None
        self.y: G = None
        self.v: C = None
        self.p: G = None
        self.q: G = None
        self.o: H = None
        self.z: H = None
        self.t: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.v: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.q: F = None
        self.x: C = None
        self.z: D = None
        self.s: J = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.w: E = None
        self.y: B = None
        self.x: B = None
        self.z: D = None
        self.v: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: J = None
        self.y: G = None
        self.v: C = None
        self.p: G = None
        self.q: G = None
        self.o: H = None
        self.z: H = None
        self.t: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: D = None
        self.v: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.q: F = None
        self.x: C = None
        self.z: D = None
        self.s: J = None
        self.txt = txt

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

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

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

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