silver@tyr:~/euler/4$ time lua 4.lua
 =  pal: 906609 = 993 * 913

real    0m0.031s
user    0m0.028s
sys     0m0.002s
silver@tyr:~/euler/4$ time lua 4.lua
 =  pal: 99000099 = 9999 * 9901

real    0m0.036s
user    0m0.032s
sys     0m0.004s
silver@tyr:~/euler/4$ time lua 4.lua
 =  pal: 9966006699 = 99979 * 99681

real    0m3.527s
user    0m3.522s
sys     0m0.002s