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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.r: D = None
        self.t: F = None
        self.p: B = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.w: F = None
        self.y: F = None
        self.q: E = None
        self.r: B = None
        self.s: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.t: B = None
        self.z: B = None
        self.u: E = None
        self.o: D = None
        self.txt = txt

h = A("h")
a = B("a")
l = C("l")
j = D("j")
f = E("f")
m = F("m")
b = G("b")
c = B("c")
g = C("g")
n = G("n")

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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.r: D = None
        self.t: F = None
        self.p: B = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: A = None
        self.w: F = None
        self.y: F = None
        self.q: E = None
        self.r: B = None
        self.s: E = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.p: D = None
        self.t: B = None
        self.z: B = None
        self.u: E = None
        self.o: D = None
        self.txt = txt

h = A("h")
a = B("a")
l = C("l")
j = D("j")
f = E("f")
m = F("m")
b = G("b")
c = B("c")
g = C("g")
n = G("n")

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