hdoj 4572 Bottles Arrangement

#include <stdio.h>
int main()
{
    int n, m;
    while (scanf("%d %d", &m, &n) != EOF)
    {
        int ans = 0;
        int t = m;
        for (int i = n; i != 1; i -= 2)
        {
            ans += t*2;
            t--;
        }
        ans += t;
        printf("%d\n", ans);
    }
    return 0;
}