The answer is 6...Have a look.

The flag has horizontal bands of red (on the top) and blue (on the bottom), of equal width, separated by a central green band which splits into a horizontal "Y" shape, the arms of which end at the corners of the hoist side (and follow the flag's diagonals). The "Y" embraces a black isosceles triangle from which the arms are separated by narrow yellow bands; the red and blue bands are separated from the green band and its arms by narrow white stripes.
(Source: https://en.wikipedia.org/wiki/Flag_of_South_Africa)

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