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

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

class C:
    def __init__(self, txt: str):
        self.u: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: G = None
        self.x: E = None
        self.s: F = None
        self.v: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.z: J = None
        self.y: G = None
        self.q: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.t: A = None
        self.u: J = None
        self.o: F = None
        self.z: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: G = None
        self.u: F = None
        self.q: E = None
        self.o: A = None
        self.t: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: C = None
        self.y: G = None
        self.r: C = None
        self.s: I = None
        self.u: F = None
        self.x: I = None
        self.w: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.p: B = None
        self.o: G = None
        self.x: E = None
        self.s: F = None
        self.v: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.z: J = None
        self.y: G = None
        self.q: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.t: A = None
        self.u: J = None
        self.o: F = None
        self.z: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: H = None
        self.s: G = None
        self.u: F = None
        self.q: E = None
        self.o: A = None
        self.t: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.z: A = None
        self.p: C = None
        self.y: G = None
        self.r: C = None
        self.s: I = None
        self.u: F = None
        self.x: I = None
        self.w: C = None
        self.txt = txt

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

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