class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.v: B = None
        self.u: C = None
        self.t: D = None
        self.o: B = None
        self.p: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.o: I = None
        self.w: I = None
        self.u: C = None
        self.y: A = None
        self.p: J = None
        self.z: F = None
        self.q: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.y: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: D = None
        self.r: B = None
        self.z: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: G = None
        self.q: F = None
        self.u: J = None
        self.p: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: F = None
        self.x: F = None
        self.t: G = None
        self.o: C = None
        self.u: A = None
        self.p: A = None
        self.r: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.o: I = None
        self.w: I = None
        self.u: C = None
        self.y: A = None
        self.p: J = None
        self.z: F = None
        self.q: F = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.w: I = None
        self.y: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: D = None
        self.r: B = None
        self.z: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.r: G = None
        self.q: F = None
        self.u: J = None
        self.p: J = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: F = None
        self.x: F = None
        self.t: G = None
        self.o: C = None
        self.u: A = None
        self.p: A = None
        self.r: B = None
        self.txt = txt

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

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