Count Ones in a Binary String

Your task is to count the number of occurrences of the digit 1 in a given binary string. The string represents a binary number and may even be empty. For example, if the input is 1101010, then the output should be 4 because there are four '1's.

This problem tests your basic string manipulation skills and understanding of standard input/output operations.

inputFormat

A single line containing a binary string (composed of characters '0' and '1'). The string may be empty to represent the number zero.

outputFormat

A single integer that represents the count of '1's in the given binary string.## sample

0000000

0