class A:
    def __init__(self, txt: str):
        self.q: C = None
        self.v: E = None
        self.r: D = None
        self.u: I = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.y: G = None
        self.t: F = None
        self.u: I = None
        self.v: E = None
        self.w: H = None
        self.q: E = None
        self.r: F = None
        self.z: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.q: I = None
        self.p: B = None
        self.v: H = None
        self.y: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: A = None
        self.q: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.u: D = None
        self.s: I = None
        self.q: F = None
        self.v: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: H = None
        self.r: H = None
        self.p: I = None
        self.z: E = None
        self.x: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: B = None
        self.z: E = None
        self.x: G = None
        self.r: B = None
        self.p: D = None
        self.s: C = None
        self.y: G = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: G = None
        self.y: G = None
        self.t: F = None
        self.u: I = None
        self.v: E = None
        self.w: H = None
        self.q: E = None
        self.r: F = None
        self.z: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.q: I = None
        self.p: B = None
        self.v: H = None
        self.y: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: A = None
        self.q: I = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.u: D = None
        self.s: I = None
        self.q: F = None
        self.v: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: F = None
        self.o: H = None
        self.r: H = None
        self.p: I = None
        self.z: E = None
        self.x: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.u: E = None
        self.v: B = None
        self.z: E = None
        self.x: G = None
        self.r: B = None
        self.p: D = None
        self.s: C = None
        self.y: G = None
        self.txt = txt

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

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