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

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

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

class D:
    def __init__(self, txt: str):
        self.w: D = None
        self.q: B = None
        self.x: H = None
        self.z: C = None
        self.u: C = None
        self.r: A = None
        self.s: I = None
        self.o: H = None
        self.t: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: H = None
        self.q: C = None
        self.w: I = None
        self.o: B = None
        self.p: D = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.v: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.y: D = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.w: D = None
        self.q: B = None
        self.x: H = None
        self.z: C = None
        self.u: C = None
        self.r: A = None
        self.s: I = None
        self.o: H = None
        self.t: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: H = None
        self.q: C = None
        self.w: I = None
        self.o: B = None
        self.p: D = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.v: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: F = None
        self.y: D = None
        self.txt = txt

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

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

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