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Let
and
be two circles that are externally tangent at point
. We have a point
on
and a point
on
such that
is an interior point of segment
. Let
be a circle that passes through points
and
and intersects circles
and
another time at points
and
respectively. Let
be the circumscribed circle of triangle
. Prove that the centres of circles
and
all lie on the same circle.



















