#define SIZE 20    /* work on 20 elements */

int data[SIZE];    /* some data */
int twice[SIZE];   /* twice some data */

main()
{
    int index;   /* index into the data */

    for (index = 0; index < SIZE; index++) {
    data[index] = index;
    twice[index] = index * 2;
    }
    return (0);
}