In the ancient legend, there are four magical birds: the two-tailed bird (one head and two tails), the three-tailed bird (one head and 3 tails), the six-tailed bird (one head and six tails) and the eight-tailed bird (two heads and eight tails). The number of two-talied birds is 5 more than twice as many as the number of eight-tailed birds. The number of three-tailed birds is 2 more than half the number of six-talied bird. Given that the total number of their tails is 2 less than four times as many as the total number of their heads, and the difference between the total number of their heads and their tails is 241. How many three-tailed birds are there? 
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