function main(input) {
  const A = parseInt(input.split(" ")[0], 10);
  const B = parseInt(input.split(" ")[1], 10);
  const C = parseInt(input.split(" ")[2], 10);
  var arr=[A+10*B+C, 10*A+B+C, 10*C+A+B]
  console.log(Math.max.apply(null, arr));
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));