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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.p: F = None
        self.t: E = None
        self.s: I = None
        self.v: H = None
        self.r: I = None
        self.u: D = None
        self.x: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.w: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: J = None
        self.t: B = None
        self.u: C = None
        self.r: G = None
        self.v: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: H = None
        self.y: D = None
        self.x: C = None
        self.t: C = None
        self.s: J = None
        self.u: A = None
        self.r: C = None
        self.w: G = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: G = None
        self.t: A = None
        self.x: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.o: G = None
        self.p: F = None
        self.t: E = None
        self.s: I = None
        self.v: H = None
        self.r: I = None
        self.u: D = None
        self.x: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: D = None
        self.w: I = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: J = None
        self.t: B = None
        self.u: C = None
        self.r: G = None
        self.v: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: H = None
        self.y: D = None
        self.x: C = None
        self.t: C = None
        self.s: J = None
        self.u: A = None
        self.r: C = None
        self.w: G = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.s: B = None
        self.v: G = None
        self.t: A = None
        self.x: C = None
        self.txt = txt

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

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