class A:
    def __init__(self, txt: str):
        self.y: G = None
        self.r: H = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: E = None
        self.t: C = None
        self.x: E = None
        self.r: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.q: E = None
        self.v: F = None
        self.w: I = None
        self.z: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: E = None
        self.y: B = None
        self.p: D = None
        self.s: D = None
        self.o: G = None
        self.r: C = None
        self.w: C = None
        self.z: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.r: B = None
        self.w: B = None
        self.v: C = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.p: E = None
        self.t: C = None
        self.x: E = None
        self.r: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.q: E = None
        self.v: F = None
        self.w: I = None
        self.z: H = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.x: A = None
        self.t: E = None
        self.y: B = None
        self.p: D = None
        self.s: D = None
        self.o: G = None
        self.r: C = None
        self.w: C = None
        self.z: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.p: H = None
        self.r: B = None
        self.w: B = None
        self.v: C = None
        self.txt = txt

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

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