class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.z: J = None
        self.v: E = None
        self.q: J = None
        self.o: D = None
        self.y: J = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: J = None
        self.u: D = None
        self.q: I = None
        self.s: E = None
        self.w: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: E = None
        self.x: A = None
        self.v: G = None
        self.y: E = None
        self.p: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: D = None
        self.q: D = None
        self.y: H = None
        self.u: C = None
        self.x: G = None
        self.t: C = None
        self.s: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.p: J = None
        self.s: B = None
        self.y: E = None
        self.r: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: C = None
        self.y: J = None
        self.r: B = None
        self.o: J = None
        self.s: A = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: J = None
        self.u: D = None
        self.q: I = None
        self.s: E = None
        self.w: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: E = None
        self.x: A = None
        self.v: G = None
        self.y: E = None
        self.p: F = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.p: D = None
        self.q: D = None
        self.y: H = None
        self.u: C = None
        self.x: G = None
        self.t: C = None
        self.s: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.u: B = None
        self.p: J = None
        self.s: B = None
        self.y: E = None
        self.r: A = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: C = None
        self.y: J = None
        self.r: B = None
        self.o: J = None
        self.s: A = None
        self.txt = txt

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

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

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