class A:
    def __init__(self, txt: str):
        self.o: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: E = None
        self.p: A = None
        self.x: H = None
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: J = None
        self.p: G = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: E = None
        self.v: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: D = None
        self.q: B = None
        self.w: D = None
        self.v: F = None
        self.s: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: A = None
        self.x: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: E = None
        self.p: A = None
        self.x: H = None
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: D = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.s: J = None
        self.p: G = None
        self.txt = txt

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: E = None
        self.v: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.r: D = None
        self.q: B = None
        self.w: D = None
        self.v: F = None
        self.s: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.p: A = None
        self.x: D = None
        self.txt = txt

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

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