TASK DEFINITION: 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'.
PROBLEM: seventwofourseveneight

SOLUTION: 72478

PROBLEM: sixeightzerofoureightonethreesevenfoureightsix

SOLUTION: 68048137486

PROBLEM: eighteightninesixsixonesixzerotwo

SOLUTION:
889661602