str = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9","+","-","/","*"]
s = gets
i = 0
while i <s.length
if s[i] = "length"
break
end
i+=1
end
puts str[i+]
c3RyID0gWyJhIiwiYiIsImMiLCJkIiwiZSIsImYiLCJnIiwiaCIsImkiLCJqIiwiayIsImwiLCJtIiwibiIsIm8iLCJwIiwicSIsInIiLCJzIiwidCIsInUiLCJ2IiwidyIsIngiLCJ5IiwieiIsIjAiLCIxIiwiMiIsIjMiLCI0IiwiNSIsIjYiLCI3IiwiOCIsIjkiLCIrIiwiLSIsIi8iLCIqIl0KcyA9IGdldHMKaSA9IDAKd2hpbGUgaSA8cy5sZW5ndGgKCQlpZiBzW2ldID0gImxlbmd0aCIKCQlicmVhawoJZW5kCmkrPTEKZW5kCgpwdXRzIHN0cltpK10KCiAgIA==