"use strict"
function main(arg) {
    //最大は1000000
    var kazua = parseInt(arg.trim().split(" ")[0]);
    var kazub = parseInt(arg.trim().split(" ")[1]);

    
    var plus = kazua + kazub;
    var minus = kazua - kazub;
    var kakeru = kazua * kazub;

    var kotae = 0;

    if(plus >= minus){
        kotae = plus;
    }else{
        kotae = minus;
    }

    if(kotae >= kakeru){
        
    }else{
        kotae = kakeru;
    }
    console.log(kotae);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));
