class A:
    def __init__(self, txt: str):
        self.y: J = None
        self.s: F = None
        self.o: J = None
        self.x: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: F = None
        self.v: D = None
        self.s: I = None
        self.x: F = None
        self.r: G = None
        self.txt = txt

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.t: C = None
        self.v: I = None
        self.z: E = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: A = None
        self.x: F = None
        self.v: I = None
        self.s: C = None
        self.o: E = None
        self.t: I = None
        self.r: C = None
        self.y: F = None
        self.w: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.t: F = None
        self.v: D = None
        self.s: I = None
        self.x: F = None
        self.r: G = None
        self.txt = txt

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.r: F = None
        self.t: C = None
        self.v: I = None
        self.z: E = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: A = None
        self.x: F = None
        self.v: I = None
        self.s: C = None
        self.o: E = None
        self.t: I = None
        self.r: C = None
        self.y: F = None
        self.w: B = None
        self.txt = txt

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

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