B"Petya loves lucky numbers very much. Everybody knows that lucky numbers are positive integers whose decimal record contains only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not. Petya brought home string s with the length of n. The string only consists of lucky digits. The digits are numbered from the left to the right starting with 1. Now Petya should execute m queries of the following form: Subsequence of a string s is a string that can be obtained from s by removing zero or more of its elements. A string is called non-decreasing if each successive digit is not less than the previous one. Help Petya process the requests. The first line contains two integers n and m (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89106, xe2 x80 x891 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89m xe2 x80 x89 xe2 x89 xa4 xe2 x80 x893 xc2 xb7105) -- the length of the string s and the number of queries correspondingly. The second line contains n lucky digits without spaces -- Petya's initial string. Next m lines contain queries in the form described in the statement. For each query count print an answer on a single line. In the first sample the chronology of string s after some operations are fulfilled is as follows (the sought maximum subsequence is marked with bold): "...