Consider a square array of dots, colored red or blue, with 20 rows and 20 columns. Whenever two dots of the same color are adjacent in the same row or column; they are joined by a segment of their common color. Adjacent dots of unlike colors are joined by a black segment. There are 219 red dots, 39 of them on the border of the array, not at the corners. There are 237 black segments. How many blue segments are there?
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