class A:
    def __init__(self, txt: str):
        self.v: I = None
        self.x: J = None
        self.r: G = None
        self.w: J = None
        self.q: E = None
        self.o: I = None
        self.p: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.y: G = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: D = None
        self.u: D = None
        self.t: H = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.w: H = None
        self.y: G = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: C = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.v: D = None
        self.u: D = None
        self.t: H = None
        self.txt = txt

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

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

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

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

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