Add up digits multiplied by their position

Write a program that reads numbers from the input, and outputs the result of adding each digit multiplied by its position. We consider the most significant digit to be at position 1, the second most significant digit to be at position 2, and so on and so forth.

For example, given 785902, the program will print 86, which is the result of evaluating $1\times{}7+2\times{}8+3\times{}5+4\times{}9+5\times{}0+6\times{}2$ .

Input

The input has an arbitrary number of cases. Each one is a positive natural number in one line.

Output

For each case, the output contains a line with the corresponding result of adding digits multiplied by their positions.

Observation

Massive storage solutions are not accepted (like strings or vectors). Read numbers from the input into variables of type int; for instance, with cin $>>$ a, and solve the problem operating with integers using +, -, , /, and %.

Evaluation over 10 points:

Slow solution: 5 points.
Fast solution: 10 points.

We understand as fast solution one which is correct, has linear cost and passes the public and private tests. We understand as slow solution one which is not fast, but it is correct and passes the public tests.

Problem information

Author: PRO1

Generation: 2026-01-25T22:58:29.390Z