function main(input = ``) {
  let lines = input.split('\n');

  return Array.from(lines[0]).reduce((sum, c) => {
    if (!isNaN(parseInt(c))) {
      return sum + parseInt(c);
    } else {
      return sum;
    }
  }, 0);
}

const { readFileSync, existsSync } = require('fs');
const stdin = '/dev/stdin';

if (existsSync(stdin)) {
  const input = readFileSync(stdin, 'utf8');
  console.log(main(input));
}

module.exports = main;