Go Chocolates By Numbers
func chocolatesByNumbers(n, m int) int {
	var gcd func(n, m int) int
	gcd = func(n, m int) int {
		if n%m == 0 {
			return m
		}

		return gcd(m, n%m)
	}

	return n / gcd(n, m)
}

This uses the greatest common divisor to figure out how many chocolates get eaten before the pattern repeats.