#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;


//resize(vector, {v1,v2,v3});

void resize(int& val , vector<int>::iterator itr){val = 0;}
void resize(long long& val , vector<int>::iterator itr){val = 0;}
void resize(double& val , vector<int>::iterator itr){val = 0;}

template<class T>
void resize(vector<T>& vec, vector<int>::iterator itr){
	vec.resize(*itr);
	for(int i=0; i<*itr; i++){
		resize(vec[i], itr+1);
	}
}

template<class T>
void resize(T& vec, vector<int> sz){
	resize(vec, sz.begin());
}

int main(){
	string s;
	cin >> s;
	int n = s.size();
	int m = n/5;

	vector<vector<vector<vector<vector<int>>>>> dp;
	resize(dp, {m+1,m+1,m+1,m+1,m+1});

	string kuroi = "KUROI?";

	int check = 0;
	for(int i=0; i<5; i++){
		check |= 1<<(kuroi[i]-'A');
	}
	check = ~check;

	dp[0][0][0][0][0] = 1;
	for(int x=0; x<n; x++){
		if(s[x] != '?') if( check & (1<<(s[x]-'A') )){
			continue;
		}
/*
		vector<vector<vector<vector<vector<int>>>>> dp_;
		resize(dp_, {m+1,m+1,m+1,m+1,m+1});
		for(int k=0; k<=m; k++)
		for(int u=0; u<=k; u++)
		for(int r=0; r<=u; r++)
		for(int o=0; o<=r; o++)
		for(int i=0; i<=o; i++){
*/

		for(int k=m; k>=0; k--)
		for(int u=k; u>=0; u--)
		for(int r=u; r>=0; r--)
		for(int o=r; o>=0; o--)
		for(int i=o; i>=0; i--){
			int& pos = dp[k][u][r][o][i];
			if(pos==0) continue;
			pos = 0;
			if(s[x] == '?'){
				dp[min(m,k+1)][u][r][o][i] = 1;
				dp[k][min(k,u+1)][r][o][i] = 1;
				dp[k][u][min(u,r+1)][o][i] = 1;
				dp[k][u][r][min(r,o+1)][i] = 1;
				dp[k][u][r][o][min(o,i+1)] = 1;
			}else if(s[x]=='K'){
				dp[min(m,k+1)][u][r][o][i] = 1;
			}else if(s[x] == 'U'){
				dp[k][min(k,u+1)][r][o][i] = 1;
			}else if(s[x] == 'R'){
				dp[k][u][min(u,r+1)][o][i] = 1;
			}else if(s[x] == 'O'){
				dp[k][u][r][min(r,o+1)][i] = 1;
			}else if(s[x] == 'I'){
				dp[k][u][r][o][min(o,i+1)] = 1;
			}
		}
		//swap(dp, dp_);
	}

	int ans = 0;

	for(int k=0; k<=m; k++)
	for(int u=0; u<=k; u++)
	for(int r=0; r<=u; r++)
	for(int o=0; o<=r; o++)
	for(int i=0; i<=o; i++){
		int& pos = dp[k][u][r][o][i];
		if(pos==0) continue;
		ans = max(ans, i);
	}
	cout << ans << endl;

	return 0;
}