function main(input) {
    const args = input.split(' ');
    let A = parseInt(args[0]);
    let B = parseInt(args[1]);
    let ans = Math.max(A + B, Math.max(A - B, A * B));
    if (ans === -0) ans = 0;
    console.log(ans);
}
 
main(require('fs').readFileSync('/dev/stdin', 'utf8'));