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

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

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.v: B = None
        self.t: E = None
        self.p: E = None
        self.z: D = None
        self.y: B = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.w: B = None
        self.p: F = None
        self.s: G = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: D = None
        self.s: H = None
        self.t: G = None
        self.r: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: D = None
        self.q: C = None
        self.t: D = None
        self.p: E = None
        self.s: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: I = None
        self.o: A = None
        self.t: F = None
        self.v: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.v: B = None
        self.t: E = None
        self.p: E = None
        self.z: D = None
        self.y: B = None
        self.r: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.w: B = None
        self.p: F = None
        self.s: G = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: D = None
        self.s: H = None
        self.t: G = None
        self.r: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: A = None
        self.r: D = None
        self.q: C = None
        self.t: D = None
        self.p: E = None
        self.s: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: I = None
        self.o: A = None
        self.t: F = None
        self.v: C = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.txt = txt

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

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