What on earth do you need an array with 25,000,000,000,000,000 elements for? Bear in mind that if each elements takes up 8 bytes then this array is 200,000,000,000,000,000 bytes, 195312500000000 KiloBytes, 190734863281.25 MegaBytes, 186264514.9 GigaBytes, 181898.9 TeraBytes, 177.6 PetaBytes.

Your not going to find a computer with that amount of memory for a long time yet.....