# @param {String} s

# @return {Integer}

def roman_to_int(s)

#Contruct a conversion map.

valueMap = {'I' => 1, 'V' => 5, 'X' => 10, 'L' => 50, 'C' => 100, 'D' => 500, 'M' => 1000}

result = 0

accumulator = 0

currentMaxUnit = 0

s.each_char do |ch|

if result < valueMap[ch]

result = valueMap[ch] - result

currentMaxUnit = valueMap[ch]

else

if valueMap[ch] < currentMaxUnit

accumulator += result

result = 0

currentMaxUnit = valueMap[ch]

end

result += valueMap[ch]

end

end

accumulator += result

end

puts roman_to_int 'I'

puts roman_to_int 'V'

puts roman_to_int 'IVM'

puts roman_to_int "MCMXCVI" # 1996