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

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: J = None
        self.v: G = None
        self.y: G = None
        self.s: D = None
        self.x: F = None
        self.r: E = None
        self.w: E = None
        self.u: D = None
        self.q: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: E = None
        self.v: A = None
        self.t: A = None
        self.r: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: J = None
        self.x: A = None
        self.u: C = None
        self.r: A = None
        self.y: C = None
        self.v: I = None
        self.z: A = None
        self.p: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.q: C = None
        self.z: E = None
        self.o: J = None
        self.t: C = None
        self.u: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: E = None
        self.x: C = None
        self.y: A = None
        self.r: I = None
        self.t: C = None
        self.w: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: D = None
        self.r: E = None
        self.o: J = None
        self.s: J = None
        self.x: D = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: J = None
        self.v: G = None
        self.y: G = None
        self.s: D = None
        self.x: F = None
        self.r: E = None
        self.w: E = None
        self.u: D = None
        self.q: F = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: E = None
        self.v: A = None
        self.t: A = None
        self.r: B = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.s: J = None
        self.x: A = None
        self.u: C = None
        self.r: A = None
        self.y: C = None
        self.v: I = None
        self.z: A = None
        self.p: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: B = None
        self.q: C = None
        self.z: E = None
        self.o: J = None
        self.t: C = None
        self.u: I = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: E = None
        self.x: C = None
        self.y: A = None
        self.r: I = None
        self.t: C = None
        self.w: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.t: D = None
        self.r: E = None
        self.o: J = None
        self.s: J = None
        self.x: D = None
        self.txt = txt

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

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

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