#!/usr/bin/python3

text = input()
word = "KSP"
n = len(text)
m = len(word)

dp = [[0] * m for _ in range(n)]
dp[0][0] = int(text[0] == "K")

for i in range(1, n):
    for j in range(m):
        dp[i][j] = dp[i-1][j] + int(text[i] == word[j]) * (1 if j == 0 else dp[i-1][j-1])

print(dp[-1][-1])