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

class B:
    def __init__(self, txt: str):
        self.t: F = None
        self.s: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.v: F = None
        self.q: A = None
        self.z: G = None
        self.t: D = None
        self.o: A = None
        self.u: J = None
        self.p: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.s: C = None
        self.p: H = None
        self.u: H = None
        self.y: J = None
        self.z: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: H = None
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.o: B = None
        self.u: J = None
        self.q: B = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.t: F = None
        self.s: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.w: A = None
        self.v: F = None
        self.q: A = None
        self.z: G = None
        self.t: D = None
        self.o: A = None
        self.u: J = None
        self.p: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.x: C = None
        self.s: C = None
        self.p: H = None
        self.u: H = None
        self.y: J = None
        self.z: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: H = None
        self.x: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: G = None
        self.o: B = None
        self.u: J = None
        self.q: B = None
        self.txt = txt

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

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

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

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