public static long largestRectangle(List<int> h)
    {
        long max = 0;
        for(int i=0;i<h.Count;i++)
        {
            int n = h[i];
            int l = 0;
            for(int j=i-1;j>=0;j--)
            {
                int nl = h[j];
                if (nl < n) break;
                l++;
            }
            int r = 0;
            for(int j=i+1;j<h.Count;j++)
            {
                int nr = h[j];
                if (nr < n) break;
                r++;
            }
            long a = (long)n*(long)(l+r+1);
            if (a > max) max = a;
        }
        return max;
    }