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

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.o: D = None
        self.v: G = None
        self.p: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: A = None
        self.v: F = None
        self.t: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.y: D = None
        self.v: C = None
        self.p: I = None
        self.w: C = None
        self.u: A = None
        self.z: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.v: D = None
        self.p: F = None
        self.z: F = None
        self.r: F = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.o: D = None
        self.v: G = None
        self.p: G = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: A = None
        self.v: F = None
        self.t: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: D = None
        self.y: D = None
        self.v: C = None
        self.p: I = None
        self.w: C = None
        self.u: A = None
        self.z: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.v: D = None
        self.p: F = None
        self.z: F = None
        self.r: F = None
        self.txt = txt

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

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

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