class A:
    def __init__(self, txt: str):
        self.r: E = None
        self.o: J = None
        self.y: G = None
        self.t: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.p: B = None
        self.v: E = None
        self.t: J = None
        self.z: A = None
        self.u: G = None
        self.q: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.y: B = None
        self.s: G = None
        self.x: A = None
        self.r: C = None
        self.t: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.t: J = None
        self.r: J = None
        self.z: B = None
        self.y: B = None
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: I = None
        self.o: C = None
        self.r: C = None
        self.v: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: C = None
        self.t: D = None
        self.y: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.x: D = None
        self.txt = txt

m = A("m")
k = B("k")
h = C("h")
l = D("l")
f = E("f")
i = F("i")
j = G("j")
g = H("g")
n = I("n")
c = J("c")

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

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.p: B = None
        self.v: E = None
        self.t: J = None
        self.z: A = None
        self.u: G = None
        self.q: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.y: B = None
        self.s: G = None
        self.x: A = None
        self.r: C = None
        self.t: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.t: J = None
        self.r: J = None
        self.z: B = None
        self.y: B = None
        self.p: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.y: I = None
        self.o: C = None
        self.r: C = None
        self.v: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.w: C = None
        self.t: D = None
        self.y: D = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.x: D = None
        self.txt = txt

m = A("m")
k = B("k")
h = C("h")
l = D("l")
f = E("f")
i = F("i")
j = G("j")
g = H("g")
n = I("n")
c = J("c")

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