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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.x: J = None
        self.v: A = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.u: B = None
        self.q: I = None
        self.s: H = None
        self.r: A = None
        self.o: I = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: H = None
        self.x: J = None
        self.t: C = None
        self.s: J = None
        self.y: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.p: H = None
        self.t: A = None
        self.r: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: D = None
        self.o: G = None
        self.q: F = None
        self.t: G = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.x: J = None
        self.v: A = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: A = None
        self.u: B = None
        self.q: I = None
        self.s: H = None
        self.r: A = None
        self.o: I = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: H = None
        self.x: J = None
        self.t: C = None
        self.s: J = None
        self.y: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: C = None
        self.p: H = None
        self.t: A = None
        self.r: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: F = None
        self.z: D = None
        self.o: G = None
        self.q: F = None
        self.t: G = None
        self.txt = txt

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

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

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

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