# Print hackerearth

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#
#   As a beginner to the programming, Mishki came to Hackerearth platform, to become a better programmer.
#   She solved some problems and felt very confident. Later being a fan of Hackerearth, she gave a problem to her
#   friends to solve. They will be given a string containing only lower case characters (a-z), and they need to find
#   that by using the characters of the given string, how many times they can print "hackerearth"(without quotes).
#   As they are new to programming world, please help them.
#
#   Input:
#   The first line will consists of one integer N denoting the length of string.
#   Next line will contain the string Str containing only lower case characters.
#
#   Output:
#   Print one integer, denoting the number of times her friends can print "hackerearth" (without quotes).
#
#   Constraints:
#   1 <= N <= 10^6
#   Each character of string Str will be in range [a,z]
#
#
#   SAMPLE INPUT
#   13
#   aahkcreeatrha
#
#   SAMPLE OUTPUT
#   1
#
#   Explanation
#   Here by using the characters of string, her friends can print "hackerearth" (without quotes) only 1 time.
#
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