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

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.r: A = None
        self.q: F = None
        self.t: H = None
        self.y: C = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.q: B = None
        self.x: D = None
        self.t: E = None
        self.s: F = None
        self.o: D = None
        self.u: B = None
        self.y: D = None
        self.r: F = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.p: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: C = None
        self.r: A = None
        self.q: F = None
        self.t: H = None
        self.y: C = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.q: B = None
        self.x: D = None
        self.t: E = None
        self.s: F = None
        self.o: D = None
        self.u: B = None
        self.y: D = None
        self.r: F = None
        self.txt = txt

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

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