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

class B:
    def __init__(self, txt: str):
        self.u: I = None
        self.x: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: I = None
        self.w: I = None
        self.z: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.u: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.v: J = None
        self.p: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: A = None
        self.z: E = None
        self.u: I = None
        self.r: E = None
        self.q: J = None
        self.t: F = None
        self.p: J = None
        self.y: A = None
        self.o: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: D = None
        self.w: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: B = None
        self.x: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.u: I = None
        self.x: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: I = None
        self.w: I = None
        self.z: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: B = None
        self.u: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: I = None
        self.v: J = None
        self.p: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: A = None
        self.z: E = None
        self.u: I = None
        self.r: E = None
        self.q: J = None
        self.t: F = None
        self.p: J = None
        self.y: A = None
        self.o: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: D = None
        self.w: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: B = None
        self.x: F = None
        self.txt = txt

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

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