import java.util.*;

public class LongestSubstring {
    public int findLongest(String A, int n, String B, int m) {
        // write code here
        int res = 0;
        int[][] dp = new int[n + 1][m + 1];
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                if (A.charAt(i - 1) == B.charAt(j - 1)) {
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                    res = Math.max(res, dp[i][j]);
                } else {
                    dp[i][j] = 0;
                }
            }
        }
        return res;
    }
}