A. SWAP

#include <bits/stdc++.h>

using namespace std;

int main(){
    string s;
    cin >> s;

    int n = s.size();
    s = ' ' + s;

    int k = 0;

    vector <int> pf(n + 1);
    for (int i = 1; i <= n; i++) {
        pf[i] = pf[i - 1];
        if (s[i] == 'K') {
            k++;
        } else {
            pf[i]++;
        }
    }

    int ans = n;
    for (int i = k; i <= n; i++) {
        ans = min(ans, pf[i] - pf[i - k]);
    }

    cout << ans << endl;
}