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import java.util.*;
import java.io.*;

public class E {
    static String[] input;
    public static void main(String[] args) {
        FastScanner scanner = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
        int N = scanner.nextInt();
        input = new String[N];
        for(int i =0; i < N; i++) {
            input[i] = scanner.next();
        }
        int ans = recurse(N-1, input[N-1].charAt(0));
        out.println(ans);
        out.flush();
    }
    
    public static int recurse(int ind, char c) {
        if (ind < 0) return 0;
        char[] line = input[ind].toCharArray();
        int pref = 0;
        while(pref < line.length && c == line[pref]) pref++;
        int suff = line.length-1;
        while(suff >= 0 && line[suff] == c) suff--;
        suff = line.length-1-suff;
        int rec = recurse(ind-1, c);
        if (rec > 0) {
            if (pref == line.length) return pref + rec * pref + 1;
            else if (pref > 0 && suff > 0) return suff + pref + 1;
            else return Math.max(pref + 1, suff + 1);
        }
        return Math.max(pref, suff);
    }
    
    public static class FastScanner {
        BufferedReader br;
        StringTokenizer st;
        
        public FastScanner(Reader in) {
            br = new BufferedReader(in);
        }
        
        public FastScanner() {
            this(new InputStreamReader(System.in));
        }
        
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        
        int nextInt() {
            return Integer.parseInt(next());
        }
        
        long nextLong() {
            return Long.parseLong(next());
        }
        
        double nextDouble() {
            return Double.parseDouble(next());
        }
        
        String readNextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
        
        int[] readIntArray(int n) {
            int[] a = new int[n];
            for (int idx = 0; idx < n; idx++) {
                a[idx] = nextInt();
            }
            return a;
        }
    }
}
