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

class B:
    def __init__(self, txt: str):
        self.v: I = None
        self.w: G = None
        self.y: E = None
        self.p: F = None
        self.t: J = None
        self.z: A = None
        self.u: H = None
        self.x: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.w: J = None
        self.v: I = None
        self.u: A = None
        self.z: B = None
        self.p: B = None
        self.q: I = None
        self.x: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: F = None
        self.o: I = None
        self.v: J = None
        self.y: E = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.p: E = None
        self.o: E = None
        self.r: H = None
        self.v: D = None
        self.u: A = None
        self.y: B = None
        self.x: B = None
        self.s: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: I = None
        self.w: G = None
        self.y: E = None
        self.p: F = None
        self.t: J = None
        self.z: A = None
        self.u: H = None
        self.x: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.w: J = None
        self.v: I = None
        self.u: A = None
        self.z: B = None
        self.p: B = None
        self.q: I = None
        self.x: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.v: A = None
        self.u: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.u: F = None
        self.o: I = None
        self.v: J = None
        self.y: E = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.p: E = None
        self.o: E = None
        self.r: H = None
        self.v: D = None
        self.u: A = None
        self.y: B = None
        self.x: B = None
        self.s: E = None
        self.txt = txt

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

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