#include<bits/stdc++.h>
using namespace std;
 
 
int main() {
 
    string str;
    cin >> str;

    int sum =0;
    int A[11111111];

    for(char el: str){
        ++A[el];

    }

    string str2 = "KUROI";
    vector<int> vec;

    for(char el2: str2){
        vec.push_back(A[el2]);
    }

    int min = *std::min_element(vec.begin(), vec.end());
    cout<<min;
    return 0;
}