2754.rb

m = {"A+": 4.3, "A0": 4.0, "A-": 3.7,
"B+": 3.3, "B0": 3.0, "B-": 2.7,
"C+": 2.3, "C0": 2.0, "C-": 1.7,
"D+": 1.3, "D0": 1.0, "D-": 0.7,
"F": 0.0}
puts m[gets.strip.to_sym]