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

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

class C:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: I = None
        self.y: H = None
        self.q: H = None
        self.r: D = None
        self.z: H = None
        self.txt = txt

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

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: H = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: D = None
        self.w: I = None
        self.y: H = None
        self.q: H = None
        self.r: D = None
        self.z: H = None
        self.txt = txt

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

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

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

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

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

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

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.o: H = None
        self.txt = txt

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

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