class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.p: C = None
        self.r: E = None
        self.o: E = None
        self.y: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: A = None
        self.u: G = None
        self.r: C = None
        self.t: C = None
        self.v: G = None
        self.q: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.p: C = None
        self.v: D = None
        self.o: F = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: B = None
        self.w: D = None
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: D = None
        self.w: A = None
        self.q: C = None
        self.v: A = None
        self.o: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: F = None
        self.x: F = None
        self.q: A = None
        self.z: F = None
        self.y: E = None
        self.u: C = None
        self.w: C = None
        self.txt = txt

i = A("i")
f = B("f")
l = C("l")
e = D("e")
b = E("b")
n = F("n")
c = G("c")
j = D("j")

i.v = n
i.p = l
i.r = b
i.o = b
i.y = j
f.y = c
f.u = c
f.v = c
f.o = i
f.r = l
f.t = l
f.q = l
l.z = i
l.r = f
e.p = l
e.q = l
e.v = j
e.o = n
b.y = f
b.w = e
b.q = l
n.t = f
n.z = j
n.w = i
n.v = i
n.q = l
n.o = b
c.t = n
c.x = n
c.z = n
c.q = i
c.y = b
c.u = l
c.w = l
j.p = l
j.q = l
j.v = e
j.o = n
assert c.q.o.q.txt == "
class A:
    def __init__(self, txt: str):
        self.v: F = None
        self.p: C = None
        self.r: E = None
        self.o: E = None
        self.y: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.o: A = None
        self.u: G = None
        self.r: C = None
        self.t: C = None
        self.v: G = None
        self.q: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.p: C = None
        self.v: D = None
        self.o: F = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: B = None
        self.w: D = None
        self.q: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.z: D = None
        self.w: A = None
        self.q: C = None
        self.v: A = None
        self.o: E = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: F = None
        self.x: F = None
        self.q: A = None
        self.z: F = None
        self.y: E = None
        self.u: C = None
        self.w: C = None
        self.txt = txt

i = A("i")
f = B("f")
l = C("l")
e = D("e")
b = E("b")
n = F("n")
c = G("c")
j = D("j")

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