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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.p: E = None
        self.v: A = None
        self.q: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: E = None
        self.z: C = None
        self.o: G = None
        self.s: G = None
        self.p: F = None
        self.v: G = None
        self.w: G = None
        self.txt = txt

c = A("c")
b = B("b")
i = C("i")
g = D("g")
m = E("m")
h = F("h")
e = G("e")
d = G("d")
j = B("j")
f = E("f")

c.o = h
c.u = j
c.z = g
c.q = g
c.s = f
c.r = d
b.v = h
i.w = b
i.y = b
g.y = i
g.q = j
m.s = j
m.p = f
m.v = c
m.q = g
h.x = c
h.p = i
h.z = i
h.o = m
h.v = b
h.t = g
e.r = f
e.z = i
e.o = d
e.s = d
e.v = d
e.w = d
e.p = h
d.r = m
d.z = i
d.o = e
d.s = e
d.v = e
d.w = e
d.p = h
j.v = h
f.s = b
f.p = m
f.v = c
f.q = g
assert b.v.t.y.y.v.p.y.v.p.y.txt == "
class A:
    def __init__(self, txt: str):
        self.o: F = None
        self.u: B = None
        self.z: D = None
        self.q: D = None
        self.s: E = None
        self.r: G = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: B = None
        self.p: E = None
        self.v: A = None
        self.q: D = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.r: E = None
        self.z: C = None
        self.o: G = None
        self.s: G = None
        self.p: F = None
        self.v: G = None
        self.w: G = None
        self.txt = txt

c = A("c")
b = B("b")
i = C("i")
g = D("g")
m = E("m")
h = F("h")
e = G("e")
d = G("d")
j = B("j")
f = E("f")

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