B"Little Timofey likes integers a lot. Unfortunately, he is very young and can't work with very big integers, so he does all the operations modulo his favorite prime m. Also, Timofey likes to look for arithmetical progressions everywhere. One of his birthday presents was a sequence of distinct integers a1, xe2 x80 x89a2, xe2 x80 x89..., xe2 x80 x89an. Timofey wants to know whether he can rearrange the elements of the sequence so that is will be an arithmetical progression modulo m, or not. Arithmetical progression modulo m of length n with first element x and difference d is sequence of integers x, xe2 x80 x89x xe2 x80 x89+ xe2 x80 x89d, xe2 x80 x89x xe2 x80 x89+ xe2 x80 x892d, xe2 x80 x89..., xe2 x80 x89x xe2 x80 x89+ xe2 x80 x89(n xe2 x80 x89- xe2 x80 x891) xc2 xb7d, each taken modulo m. The first line contains two integers m and n (2 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89m xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89109 xe2 x80 x89+ xe2 x80 x897, 1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89105, m is prime) -- Timofey's favorite prime module and the length of the sequence. The second line contains n distinct integers a1, xe2 x80 x89a2, xe2 x80 x89..., xe2 x80 x89an (0 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89ai xe2 x80 x89< xe2 x80 x89m) -- the elements of the sequence. Print -1 if it is not possible to rearrange the elements of the sequence so that is will be an arithmetical progression modulo m. Otherwise, print two integers -- the first element of the obtained progression x (0 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89x xe2 x80 x89< xe2 x80 x89m) and its difference d (0 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89d xe2 x80 x89< xe2 x80 x89m). If there are multiple answers, print any of them. "...