using LIB;
using System;
using System.Linq;
using System.Text;
using System.Collections;
using System.Collections.Generic;

class Program
{
    public static IO IO = new IO();
    static void Main(string[] args)
    {
        string s = IO.STRING();
        int c = 0;
        int step = 0;
        int len = s.Count();
        bool[] f = new bool[len];
        int start = 0;
        int qc = 0;
        for (int i = 0; i < len; i++)
        {
            if (s[i] == '?') { qc++; }
            if (step == 0)
            {
                if (s[i] == 'K') { step = 1; start = i; }
                if (s[i] == 'U' && qc > 0)
                {
                    for (int j = i; j >= 0 && !f[j]; j--)
                    {
                        if (s[j] == '?') { step = 2; start = j; break; }
                    }
                }
                if (s[i] == 'R' && qc > 1)
                {
                    int nq = 2;
                    for (int j = i; j >= 0 && !f[j]; j--)
                    {
                        if (s[j] == '?')
                        {
                            nq--;
                            if (nq == 0) { step = 3; start = j; break; }
                        }
                    }
                }
                if (s[i] == 'O' && qc > 2)
                {
                    int nq = 3;
                    for (int j = i; j >= 0 && !f[j]; j--)
                    {
                        if (s[j] == '?')
                        {
                            nq--;
                            if (nq == 0) { step = 4; start = j; break; }
                        }
                    }
                }
                if (s[i] == 'I' && qc > 3)
                {
                    int nq = 4;
                    for (int j = i; j >= 0 && !f[j]; j--)
                    {
                        if (s[j] == '?')
                        {
                            nq--;
                            if (nq == 0) { c++; step = 0; for (int k = j; k <= i; k++) { f[k] = true; }; break; }
                        }
                    }
                }
            }
            if (step == 1 && (s[i] == 'U' || s[i] == '?')) { step = 2; }
            if (step == 2 && (s[i] == 'R' || s[i] == '?')) { step = 3; }
            if (step == 3 && (s[i] == 'O' || s[i] == '?')) { step = 4; }
            if (step == 4 && (s[i] == 'I' || s[i] == '?')) { c++; step = 0; for (int j = start; j <= i; j++) { f[j] = true; } }
        }
        IO.WRITE(c);
        IO.FLUSH();
    }
}

namespace LIB
{
    public class IO
    {
        private const int WMAX = 1000;
        private StringBuilder S = new StringBuilder();
        private T R<T>(Func<string, T> f) { return f(Console.ReadLine()); }
        private T[] R<T>(Func<string, T> f, char c) { return STRING().Split(c).Select(f).ToArray(); }
        private T[] R<T>(Func<string, T> f, int l) { T[] r = new T[l]; for (int i = 0; i < l; i++) { r[i] = R(f); } return r; }
        private T[][] R<T>(Func<string, T> f, int l, char c) { T[][] r = new T[l][]; for (int i = 0; i < l; i++) { r[i] = R<T>(f, c); } return r; }
        private void W<T>(Func<T, string> f, T v, bool lf = true) { S.Append(f(v)); if (lf == true) { S.Append('\n'); } if (S.Length >= WMAX) { FLUSH(); } }
        public string STRING() { return R(s => s); }
        public string[] STRING(char c) { return R(s => s, c); }
        public string[] STRING(int l) { return R(s => s, l); }
        public string[][] STRING(int l, char c) { return R(s => s, l, c); }
        public int INT() { return R(int.Parse); }
        public int[] INT(char c) { return R(int.Parse, c); }
        public int[] INT(int l) { return R(int.Parse, l); }
        public int[][] INT(int l, char c) { return R(int.Parse, l, c); }
        public long LONG() { return R(long.Parse); }
        public long[] LONG(char c) { return R(long.Parse, c); }
        public long[] LONG(int l) { return R(long.Parse, l); }
        public long[][] LONG(int l, char c) { return R(long.Parse, l, c); }
        public double DOUBLE() { return R(double.Parse); }
        public double[] DOUBLE(char c) { return R(double.Parse, c); }
        public double[] DOUBLE(int l) { return R(double.Parse, l); }
        public double[][] DOUBLE(int l, char c) { return R(double.Parse, l, c); }
        public void WRITE(string s, bool lf = true) { W(v => v, s, lf); }
        public void WRITE(int s, bool lf = true) { W(v => v.ToString(), s, lf); }
        public void WRITE(long s, bool lf = true) { W(v => v.ToString(), s, lf); }
        public void WRITE(double s, bool lf = true) { W(v => v.ToString(), s, lf); }
        public void FLUSH() { Console.Write(S); S.Length = 0; }
    }
}