package problems622;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringReader;
import java.util.Arrays;

public class Main {

    static int index(int M, int k, int u, int r, int o) {
        return ((k * M + u) * M + r) * M + o;
    }

    public void run() throws IOException {
        String SS = io.nextString();
        StringBuilder S = new StringBuilder(101);
        for (int i = 0; i < SS.length(); i++) {
            char c = SS.charAt(i);
            if ("KUROI?".indexOf(c) >= 0) {
                S.append(c);
            }
        }

        int M = S.length() / 5 + 1;
        int M4 = (M + 1) * (M + 1) * (M + 1) * (M + 1) + 1;
        int[][] dp = new int[2][M4];

        for (int x = 0; x < 2; x++) {
            Arrays.fill(dp[x], -1);
        }

        int ma = 0;

        dp[0][0] = 0;
        for (int i = 0; i < S.length(); i++) {
            char c = S.charAt(i);
            int[] dp1 = dp[i % 2];
            int[] dp2 = dp[(i + 1) % 2];

            System.arraycopy(dp1, 0, dp2, 0, dp2.length);

            for (int k = 0; k < M; k++) {
                for (int u = 0; u < M; u++) {
                    for (int r = 0; r < M; r++) {
                        for (int o = 0; o < M; o++) {
                            int index = index(M, k, u, r, o);
                            int now = dp1[index];
                            if (now == -1) continue;

                            if ((c == 'K' || c == '?') && k < M) {
                                int ni = index(M, k + 1, u, r, o);
                                dp2[ni] = Integer.max(dp2[ni], now);
                            }
                            if ((c == 'U' || c == '?') && u < M && k > 0) {
                                int ni = index(M, k - 1, u + 1, r, o);
                                dp2[ni] = Integer.max(dp2[ni], now);
                            }
                            if ((c == 'R' || c == '?') && r < M && u > 0) {
                                int ni = index(M, k, u - 1, r + 1, o);
                                dp2[ni] = Integer.max(dp2[ni], now);
                            }
                            if ((c == 'O' || c == '?') && o < M && r > 0) {
                                int ni = index(M, k, u, r - 1, o + 1);
                                dp2[ni] = Integer.max(dp2[ni], now);
                            }
                            if ((c == 'I' || c == '?') && o > 0) {
                                int ni = index(M, k, u, r, o - 1);
                                dp2[ni] = Integer.max(dp2[ni], now + 1);
                                ma = Integer.max(ma, now + 1);
                            }
                        }
                    }
                }
            }
        }
        System.out.println(ma);
    }

    // @formatter:off
    private static final int mod = (int) 1e9 + 7;
    final IOFast io = new IOFast();

    void main() throws IOException { try { run(); } catch (RuntimeException e) { e.printStackTrace(); } finally { io.out.flush(); } }
    public static void main(String[] args) throws IOException { new Main().main(); }

    public static String dtos(double x, int n) {
        StringBuilder sb = new StringBuilder();
        if (x < 0) {
            sb.append('-');
            x = -x;
        }
        x += Math.pow(10, -n) / 2;
        sb.append((long) x);
        sb.append(".");
        x -= (long) x;
        for (int i = 0; i < n; i++) {
            x *= 10;
            sb.append((int) x);
            x -= (int) x;
        }
        return sb.toString();
    }

    public static class IOFast {
        private BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        private PrintWriter out = new PrintWriter(System.out);

        void setStringIn(String input) throws IOException { in.close(); in = new BufferedReader(new StringReader(input)); }
        void setStringOut(ByteArrayOutputStream output) throws IOException { System.out.flush(); System.setOut(new PrintStream(output)); }
        void setStringIO(String input, ByteArrayOutputStream output) throws IOException { setStringIn(input); setStringOut(output); }

        private static int pos, readLen;
        private static final char[] buffer = new char[1024 * 8];
        private static char[] str = new char[500*8*2];
        private static boolean[] isDigit = new boolean[256];
        private static boolean[] isSpace = new boolean[256];
        private static boolean[] isLineSep = new boolean[256];

        static { for(int i = 0; i < 10; i++) { isDigit['0' + i] = true; } isDigit['-'] = true; isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true; isLineSep['\r'] = isLineSep['\n'] = true; }
        public int read() throws IOException { if(pos >= readLen) { pos = 0; readLen = in.read(buffer); if(readLen <= 0) { throw new RuntimeException(); } } return buffer[pos++]; }
        public int nextInt() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); int i = 0; int ret = 0; if(str[0] == '-') { i = 1; } for(; i < len; i++) ret = ret * 10 + str[i] - '0'; if(str[0] == '-') { ret = -ret; } return ret; }
        public long nextLong() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); int i = 0; long ret = 0; if(str[0] == '-') { i = 1; } for(; i < len; i++) ret = ret * 10 + str[i] - '0'; if(str[0] == '-') { ret = -ret; } return ret; }
        public char nextChar() throws IOException { while(true) { final int c = read(); if(!isSpace[c]) { return (char)c; } } }
        int reads(int len, boolean[] accept) throws IOException { try { while(true) { final int c = read(); if(accept[c]) { break; } if(str.length == len) { char[] rep = new char[str.length * 3 / 2]; System.arraycopy(str, 0, rep, 0, str.length); str = rep; } str[len++] = (char)c; } } catch(RuntimeException e) { ; } return len; }
        public char[] nextLine() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isLineSep); try { if(str[len-1] == '\r') { len--; read(); } } catch(RuntimeException e) { ; } return Arrays.copyOf(str, len); }
        public String nextString() throws IOException { return new String(next()); }
        public char[] next() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); return Arrays.copyOf(str, len); }
        public double nextDouble() throws IOException { return Double.parseDouble(nextString()); }
        public long[] nextLongArray(final int n) throws IOException { final long[] res = new long[n]; for(int i = 0; i < n; i++) { res[i] = nextLong(); } return res; }
        public int[] nextIntArray(final int n) throws IOException { final int[] res = new int[n]; for(int i = 0; i < n; i++) { res[i] = nextInt(); } return res; }
        public int[][] nextIntArray2D(final int n, final int k) throws IOException { final int[][] res = new int[n][]; for(int i = 0; i < n; i++) { res[i] = nextIntArray(k); } return res; }
        public int[][] nextIntArray2DWithIndex(final int n, final int k) throws IOException { final int[][] res = new int[n][k+1]; for(int i = 0; i < n; i++) { for(int j = 0; j < k; j++) { res[i][j] = nextInt(); } res[i][k] = i; } return res; }
        public double[] nextDoubleArray(final int n) throws IOException { final double[] res = new double[n]; for(int i = 0; i < n; i++) { res[i] = nextDouble(); } return res; }
    }
    // @formatter:on
}