#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

#define sz size()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(c) (c).begin(), (c).end()
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define clr(a, b) memset((a), (b) ,sizeof(a))

#define MOD 1000000007

int dp[2][22][22][22][22][22];

int main() {
    clr(dp,0);
    string s;
    cin>>s;
    string s1;
    rep(i,0,s.sz){
      if(s[i]=='K'||s[i]=='U'||s[i]=='R'||s[i]=='O'||s[i]=='I'||s[i]=='?'){
        s1 += s[i];
      }
    }
    s = "I"+s1;
    dp[0][0][0][0][0][0] = 1;
    int old = 0;
    int now = 1;
    rep(j,1,s.sz){
        rep(k,0,21){
          rep(u,0,21){
            if(u>k)continue;
            rep(r,0,21){
              if(r>u)continue;
              rep(o,0,21){
                if(o>r)continue;
                rep(i,0,21){
                  if(i>o)continue;
                  if(dp[old][k][u][r][o][i]==0)continue;
                  if(s[j]=='?'){
                    dp[now][min(20,k+1)][u][r][o][i] = dp[old][k][u][r][o][i];
                    dp[now][k][min(k,min(20,u+1))][r][o][i] = dp[old][k][u][r][o][i];
                    dp[now][k][u][min(u,min(20,r+1))][o][i] = dp[old][k][u][r][o][i];
                    dp[now][k][u][r][min(r,min(20,o+1))][i] = dp[old][k][u][r][o][i];
                    dp[now][k][u][r][o][min(o,min(20,i+1))] = dp[old][k][u][r][o][i];
                  }
                  else if(s[j]=='K'){
                    dp[now][min(20,k+1)][u][r][o][i] = dp[old][k][u][r][o][i];
                  }
                  else if(s[j]=='U'){
                    dp[now][k][min(k,min(20,u+1))][r][o][i] = dp[old][k][u][r][o][i];
                  }
                  else if(s[j]=='R'){
                    dp[now][k][u][min(u,min(20,r+1))][o][i] = dp[old][k][u][r][o][i];
                  }
                  else if(s[j]=='O'){
                    dp[now][k][u][r][min(r,min(20,o+1))][i] = dp[old][k][u][r][o][i];
                  }
                  else if(s[j]=='I'){
                    dp[now][k][u][r][o][min(o,min(20,i+1))] = dp[old][k][u][r][o][i];
                  }
                }
              }
            }
          }
        }
        clr(dp[old],0);
        old = 1-old;
        now = 1-now;
    }
    int mx = 0;
    rep(k,0,21){
          rep(u,0,21){
            rep(r,0,21){
              rep(o,0,21){
                rep(i,0,21){
                  if(dp[old][k][u][r][o][i] > 0){
                    mx = max(mx,min(k,min(u,min(r,min(o,i)))));
                  }
                }
              }
            }
          }
    }
    cout << mx << endl;
    return 0;
}