class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.w: C = None
        self.t: E = None
        self.p: I = None
        self.r: B = None
        self.x: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.p: D = None
        self.u: G = None
        self.z: J = None
        self.w: A = None
        self.s: F = None
        self.v: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: J = None
        self.t: D = None
        self.r: H = None
        self.p: J = None
        self.x: F = None
        self.z: G = None
        self.q: F = None
        self.v: D = None
        self.s: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: I = None
        self.v: I = None
        self.z: D = None
        self.q: D = None
        self.o: H = None
        self.x: I = None
        self.u: I = None
        self.r: G = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.r: D = None
        self.y: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.p: D = None
        self.u: G = None
        self.z: J = None
        self.w: A = None
        self.s: F = None
        self.v: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: J = None
        self.t: D = None
        self.r: H = None
        self.p: J = None
        self.x: F = None
        self.z: G = None
        self.q: F = None
        self.v: D = None
        self.s: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: I = None
        self.v: I = None
        self.z: D = None
        self.q: D = None
        self.o: H = None
        self.x: I = None
        self.u: I = None
        self.r: G = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.r: D = None
        self.y: F = None
        self.txt = txt

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

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

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