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: sevenfivethreethreetwofoureight
Example Output: 7533248

Example Input: fivetwoeightfivethreeninetwozerofour
Example Output: 528539204

Example Input: twofourfouronetwooneseven
Example Output:
2441217