class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: I = None
        self.w: H = None
        self.z: G = None
        self.o: D = None
        self.p: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.y: I = None
        self.r: F = None
        self.w: H = None
        self.x: C = None
        self.s: E = None
        self.q: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: D = None
        self.z: A = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: F = None
        self.x: A = None
        self.t: D = None
        self.y: F = None
        self.s: I = None
        self.o: D = None
        self.z: E = None
        self.p: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: I = None
        self.p: D = None
        self.r: C = None
        self.y: C = None
        self.u: B = None
        self.v: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.y: I = None
        self.r: F = None
        self.w: H = None
        self.x: C = None
        self.s: E = None
        self.q: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.o: I = None
        self.w: D = None
        self.z: A = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: F = None
        self.x: A = None
        self.t: D = None
        self.y: F = None
        self.s: I = None
        self.o: D = None
        self.z: E = None
        self.p: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.q: I = None
        self.p: D = None
        self.r: C = None
        self.y: C = None
        self.u: B = None
        self.v: D = None
        self.txt = txt

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

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