Sum of Digits

Given a non-negative integer (n), compute the sum of its digits. In mathematical notation, if (n) has digits (d_k, d_{k-1}, \ldots, d_0), then the result is given by (\sum_{i=0}^{k} d_i). The input is provided via standard input, and the result must be printed to standard output.

inputFormat

A single non-negative integer (n) is provided from standard input. It is guaranteed that (0 \leq n \leq 10^{18}).

outputFormat

Output the sum of the digits of (n) to standard output.## sample

5

5