import java.io.*;
import java.util.*;
import java.util.zip.Adler32;

public class Main {
    static ArrayList<Integer>[]adj;
    static Stack<Integer>st;
    static boolean[]vis;
    static int[]color;
    static int dfs(int i) {
        if (dp[i] != -1)
            return dp[i];
        int ans = 0;
        boolean found = false;
        for (int v : adj[i]){
            ans+=dfs(v);
            if (color[i]==0&&color[v]==1)
                found=true;
        }
        ans+=found?1: 0;
        return dp[i]=ans;
    }
    static int[]dp;
    public static void main(String[]args) throws Exception {
        Scanner sc = new Scanner(System.in);
        PrintWriter pw = new PrintWriter(System.out);
        char[]s = sc.nextLine().toCharArray();
        int[]cc= new int[26];
        for (int i =0;i<s.length;i++){
            int c=0;
            int lst=i;
            for (int j =i;j<s.length;j++){

                if (s[i]!=s[j]) {
                    break;
                }
                else c++;
                lst=j;
            }
            if (!(i==0||lst==s.length-1)){
                c=(c+1)/2;
            }
            i=lst;
            cc[s[i]-'a']=Math.max(cc[s[i]-'a'],c);
        }
        Arrays.sort(cc);
        pw.println(cc[24]);
        pw.flush();
    }


    static class Scanner
    {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}

        public String next() throws IOException
        {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {return Integer.parseInt(next());}

        public long nextLong() throws IOException {return Long.parseLong(next());}

        public String nextLine() throws IOException {return br.readLine();}

        public double nextDouble() throws IOException
        {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if(x.charAt(0) == '-')
            {
                neg = true;
                start++;
            }
            for(int i = start; i < x.length(); i++)
                if(x.charAt(i) == '.')
                {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                }
                else
                {
                    sb.append(x.charAt(i));
                    if(dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg?-1:1);
        }

        public boolean ready() throws IOException {return br.ready();}


    }
}