const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void async function () {
    // Write your code here
    while(line = await readline()){
        nums = await readline();
        len = parseInt(line);
        nums = nums.split(' ');
        let arr = nums.map(a => Number(a));
        let arrs = arr.sort((a,b) => a-b);
        console.log(Math.max(arrs[len-1] * arrs[len-2] * arrs[len-3], arrs[len-1] * arrs[1] * arrs[0]));
    }
}()