class A:
    def __init__(self, txt: str):
        self.o: C = None
        self.u: D = None
        self.v: C = None
        self.r: H = None
        self.p: I = None
        self.w: B = None
        self.z: E = None
        self.x: D = None
        self.y: G = None
        self.q: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: G = None
        self.s: F = None
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.o: C = None
        self.u: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.w: J = None
        self.v: J = None
        self.r: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.u: A = None
        self.r: A = None
        self.w: H = None
        self.y: E = None
        self.t: C = None
        self.s: C = None
        self.v: F = None
        self.o: D = None
        self.p: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.v: H = None
        self.z: G = None
        self.w: A = None
        self.y: E = None
        self.p: G = None
        self.o: E = None
        self.txt = txt

m = A("m")
b = B("b")
j = C("j")
k = D("k")
i = E("i")
h = F("h")
e = G("e")
c = H("c")
a = I("a")
l = J("l")

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

class B:
    def __init__(self, txt: str):
        self.w: G = None
        self.s: F = None
        self.q: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.o: C = None
        self.u: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.w: J = None
        self.v: J = None
        self.r: J = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: F = None
        self.u: A = None
        self.r: A = None
        self.w: H = None
        self.y: E = None
        self.t: C = None
        self.s: C = None
        self.v: F = None
        self.o: D = None
        self.p: C = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.v: H = None
        self.z: G = None
        self.w: A = None
        self.y: E = None
        self.p: G = None
        self.o: E = None
        self.txt = txt

m = A("m")
b = B("b")
j = C("j")
k = D("k")
i = E("i")
h = F("h")
e = G("e")
c = H("c")
a = I("a")
l = J("l")

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