function main(input) {
    const H = input.split(' ');
    const A = parseInt(H[0],10);
    const B = parseInt(H[1],10);

    const pls = A + B;
    const min = A - B;
    const kake = A * B;

    if(pls > min && pls > kake) {
      console.log(pls);
    }else if (min > pls && min > kake) {
      console.log(min);
    } else if ( min === pls){
       console.log(min); 
  }else if (pls === kake){ console.log( pls)
   }else { console.log(kake)}

}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));