class A:
    def __init__(self, txt: str):
        self.v: J = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.t: G = None
        self.o: C = None
        self.y: B = None
        self.w: G = None
        self.p: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.u: E = None
        self.w: H = None
        self.r: D = None
        self.o: H = None
        self.z: A = None
        self.v: E = None
        self.q: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.u: E = None
        self.w: H = None
        self.t: H = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: C = None
        self.t: G = None
        self.o: C = None
        self.y: B = None
        self.w: G = None
        self.p: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: H = None
        self.u: E = None
        self.w: H = None
        self.r: D = None
        self.o: H = None
        self.z: A = None
        self.v: E = None
        self.q: I = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.x: G = None
        self.u: E = None
        self.w: H = None
        self.t: H = None
        self.txt = txt

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

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

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