class A:
    def __init__(self, txt: str):
        self.r: A = None
        self.u: B = None
        self.t: A = None
        self.q: D = None
        self.s: G = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.u: A = None
        self.q: B = None
        self.x: F = None
        self.y: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.u: C = None
        self.t: G = None
        self.y: C = None
        self.r: C = None
        self.s: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: B = None
        self.u: F = None
        self.x: F = None
        self.w: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: A = None
        self.q: B = None
        self.x: F = None
        self.y: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: A = None
        self.u: C = None
        self.t: G = None
        self.y: C = None
        self.r: C = None
        self.s: A = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: B = None
        self.u: F = None
        self.x: F = None
        self.w: D = None
        self.txt = txt

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

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