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

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

class C:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: B = None
        self.p: I = None
        self.q: H = None
        self.z: G = None
        self.o: D = None
        self.r: H = None
        self.u: E = None
        self.w: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: H = None
        self.u: C = None
        self.s: F = None
        self.o: I = None
        self.z: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.q: H = None
        self.s: C = None
        self.v: A = None
        self.o: D = None
        self.t: A = None
        self.txt = txt

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

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: G = None
        self.t: B = None
        self.p: I = None
        self.q: H = None
        self.z: G = None
        self.o: D = None
        self.r: H = None
        self.u: E = None
        self.w: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: C = None
        self.x: H = None
        self.u: C = None
        self.s: F = None
        self.o: I = None
        self.z: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.q: H = None
        self.s: C = None
        self.v: A = None
        self.o: D = None
        self.t: A = None
        self.txt = txt

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

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

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

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

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