inp = require('fs').readFileSync('/dev/stdin', 'utf8').split('\n')
l = inp.shift().split(' ')
A = l[0] * 1
B = l[1] * 1
max = A + B
if (max < A - B) {
    max = A - B
}
if (max < A * B) {
    max = A * B
}
if (max === 0) {
    max = 0
}
console.log(max)