func main[] : i64
    let out: i64 = 0

    for a in 500..1000
        for b in 500..1000
            if a * b > out
                let s: str = str.from_i64(a * b)
                let s_rev: str = str.reverse(s)
                if str.equal(s, s_rev)
                    out = a * b
                mem.free(s)
                mem.free(s_rev)
    io.println_i64(out)