求助，请问怎么统计一段英文里首字母出现的次数
要统计一段英文里首字母出现的次数，怎么做？下面这种的，例如：Cryopreservation is the most efficient method for long-term preservation of mammalian sperm. However, freeze-thawing procedures may strongly impair the sperm function and survival and thus decrease the reproductive performance.
本段单词首字母出现次数：A:2 C:1 D:1 E:1 F:3 H:1 I:2 L:1 M:4 O:1 P:3 R:1 S:4 T:4
