class A:
    def __init__(self, txt: str):
        self.w: E = None
        self.t: F = None
        self.q: H = None
        self.o: C = None
        self.z: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: E = None
        self.q: G = None
        self.w: F = None
        self.y: E = None
        self.t: F = None
        self.o: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: I = None
        self.z: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.x: B = None
        self.t: G = None
        self.s: D = None
        self.o: H = None
        self.p: B = None
        self.y: J = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.r: E = None
        self.q: G = None
        self.w: F = None
        self.y: E = None
        self.t: F = None
        self.o: J = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: I = None
        self.z: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.q: G = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: C = None
        self.x: B = None
        self.t: G = None
        self.s: D = None
        self.o: H = None
        self.p: B = None
        self.y: J = None
        self.txt = txt

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

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

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