# Given: A protein string P of length at most 1000 aa.

# Return: The total weight of P. Consult the monoisotopic mass table.

# Example: SKADYEK => 821.392
require 'pp'

MASSES = { 'A' => 71.03711,
           'C' => 103.00919,
           'D' => 115.02694,
           'E' => 129.04259,
           'F' => 147.06841,
           'G' => 57.02146,
           'H' => 137.05891,
           'I' => 113.08406,
           'K' => 128.09496,
           'L' => 113.08406,
           'M' => 131.04049,
           'N' => 114.04293,
           'P' => 97.05276,
           'Q' => 128.05858,
           'R' => 156.10111,
           'S' => 87.03203,
           'T' => 101.04768,
           'V' => 99.06841,
           'W' => 186.07931,
           'Y' => 163.06333}

proteins = File.read("prtm.txt").strip.split('')

puts proteins.map { |p| MASSES[p] }.inject(:+).round(3)
