function main (input){
  const args  = input.split('');
  const s1 = parseInt(args[0],10);
  const s2 = parseInt(args[1],10);
  const s3 = parseInt(args[2],10);
  
  const sum = s1 + s2 + s3 ;
  
  console.log(sum);
}
 
 const input = require('fs').readFileSync('/dev/stdin', 'utf8');
 
 main (input);