In this task you will be given a string that only contains single digit numbers spelled out. The input string will not contain spaces between the different numbers. Your task is to return the number that the string spells out. The string will spell out each digit of the number for example '1726' will be 'oneseventwosix' instead of 'one thousand seven hundred six'.

Example Input: sevenseveneightoneseven
Example Output: 77817

Example Input: zerotwothreeeightzerozerofiveseventwo
Example Output: 023800572

Example Input: fiveonefivesixfivenineseven
Example Output:
5156597