class A:
    def __init__(self, txt: str):
        self.s: E = None
        self.u: E = None
        self.w: I = None
        self.p: E = None
        self.v: F = None
        self.y: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.v: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: A = None
        self.r: J = None
        self.v: H = None
        self.q: H = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.q: A = None
        self.y: G = None
        self.u: E = None
        self.v: D = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.v: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.s: A = None
        self.r: J = None
        self.v: H = None
        self.q: H = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.q: A = None
        self.y: G = None
        self.u: E = None
        self.v: D = None
        self.txt = txt

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

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

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

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