The task is to generate the correct answer for a given math problem.

Ex Input:
Problem: meena wrote all the numbers from 1 to 29,999 inclusive . how many digits did she write in total ?

Ex Output:
138,889


Ex Input:
Problem: the average of 10 numbers is 0 . in those 10 , at the least , how many may be greater than or equal to zero ?

Ex Output:
1


Ex Input:
Problem: the average marks of 30 students in a class is 100 . but a student mark is wrongly noted as 70 instead of 10 then find the correct average marks ?

Ex Output:

c ) 98