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import java.util.*;
import java.io.*;
 
public class Main {
    static FastScanner sc = new FastScanner(System.in);
    static PrintWriter pw = new PrintWriter(System.out);
    static StringBuilder sb = new StringBuilder();
    public static void main(String[] args) throws Exception {
        int n = sc.nextInt();
        char[][] p = new char[n][];
        for (int i = 0; i < n; i++) {
            p[i] = sc.next().toCharArray();
        }
        int ans = 0;
        for (char c = 'a'; c <= 'z'; c++) {
            int pre = 0;
            int nxt = 0;
            for (int i = 0; i < n; i++) {
                if (isAll(p[i], c)) {
                    nxt = (pre + 1) * p[i].length + pre;
                } else {
                    nxt = largestSub(p[i], c);
                    if (pre > 0) nxt = Math.max(nxt, prefix(p[i], c) + 1 + suffix(p[i], c));
                }
                //pw.println(pre + " " + nxt + " " + c + " " + i);
                pre = nxt;
            }
            ans = Math.max(ans, pre);
        }
        pw.println(ans);
        pw.flush();
    }
    
    static int prefix(char[] str, char c) {
        int ans = 0;
        while (ans < str.length && str[ans] == c) ans++;
        return ans;
    }
 
    static int suffix(char[] str, char c) {
        int ans = str.length - 1;
        while (ans >= 0 && str[ans] == c) ans--;
        return str.length - 1 - ans;
    }
 
    static boolean isAll(char[] str, char c) {
        for (int i = 0; i < str.length; i++) {
            if (str[i] != c)
                return false;
        }
        return true;
    }
 
    static int largestSub(char[] str, char c) {
        if (isAll(str, c))
            return str.length;
        int ans = 0;
        int cnt = 0;
        for (int i = 0; i <= str.length; i++) {
            if (i == str.length || str[i] != c) {
                ans = Math.max(ans, cnt);
                cnt = 0;
            } else if (i < str.length) {
                cnt++;
            }
        }
        return ans;
    }
    
    static class GeekInteger {
        public static void save_sort(int[] array) {
            shuffle(array);
            Arrays.sort(array);
        }
 
        public static int[] shuffle(int[] array) {
            int n = array.length;
            Random random = new Random();
            for (int i = 0, j; i < n; i++) {
                j = i + random.nextInt(n - i);
                int randomElement = array[j];
                array[j] = array[i];
                array[i] = randomElement;
            }
            return array;
        }
        
        public static void save_sort(long[] array) {
            shuffle(array);
            Arrays.sort(array);
        }
 
        public static long[] shuffle(long[] array) {
            int n = array.length;
            Random random = new Random();
            for (int i = 0, j; i < n; i++) {
                j = i + random.nextInt(n - i);
                long randomElement = array[j];
                array[j] = array[i];
                array[i] = randomElement;
            }
            return array;
        }
 
    }
}

class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;
    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken("\n");
    }

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

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

    public double nextDouble() {
         return Double.parseDouble(next());
    }
    
    public String[] nextArray(int n) {
        String[] a = new String[n];
        for (int i = 0; i < n; i++)
            a[i] = next();
        return a;
    }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    }
}
