var roman = {
  'I':1,
  'V': 5,
  'X': 10,
  'L': 50,
  'C': 100,
  'D': 500,
  'M': 1000,
}
const romanNumeral =  string => {

  var arr = string.split('')
  var value = 0
  if(arr.length === 1) {
    return roman[string]
  }
  if (arr.length === 0) {
    return value;
  }
  if (roman[arr[0]] == null || roman[arr[1]] == null) {
    return "null"
  }
  if(arr.length - 1 === 1 && roman[arr[0]] > roman[arr[1]]) {
    return roman[arr[0]] + roman[arr[1]]
  }
  if(arr.length - 1 === 1 && roman[arr[0]] < roman[arr[1]]) {
    return roman[arr[1]] - roman[arr[0]]
  }
  for (let i = 0; i < arr.length - 1 ; i++) {
    //first lets pull the romanNumeral up

    if(arr.length - 1 === i + 1 && roman[arr[i]] > roman[arr[i + 1]]) {
      value += roman[arr[i + 1]]
    } else {
      if(roman[arr[i]] === roman[arr[i + 1]]) {
        value += roman[arr[i]]
      }
      if(roman[arr[i]] >= roman[arr[i + 1]]) {
        if(roman[arr[i]] >= roman[arr[i + 1]] && i > 0 && roman[arr[i]] >= roman[arr[i -1]]) {
          } else {
            value += roman[arr[i]]
          }
      } else {
        value += roman[arr[i+1]] - roman[arr[i]]
      }
    }
  }
  return value
}