#include <stdio.h>

int main()
{
    int n, spaceleft, spacebetween, i;

    printf("How big?\n");
    scanf("%d", &n);

    spaceleft = n - 1;
    spacebetween = -1;  /* when we add 2 after the first row, this will become 1 */
    while (spaceleft >= 0) {
        for (i = 0; i < spaceleft; i++)
            putchar(' ');
        putchar('*');
        if (spacebetween > 0) {
            for (i = 0; i < spacebetween; i++)
                putchar(' ');
            putchar('*');
        }
        putchar('\n');
        spaceleft--;
        spacebetween += 2;
    }
    return 0;
}