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

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.y: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.x: J = None
        self.w: H = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: J = None
        self.s: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: A = None
        self.z: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.r: F = None
        self.u: J = None
        self.w: G = None
        self.p: A = None
        self.o: G = None
        self.v: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: B = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.y: D = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.y: E = None
        self.x: J = None
        self.w: H = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.z: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: J = None
        self.s: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: A = None
        self.z: I = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.r: F = None
        self.u: J = None
        self.w: G = None
        self.p: A = None
        self.o: G = None
        self.v: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.y: B = None
        self.txt = txt

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

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