public static String abbreviation(String a, String b) {
        // Write your code here
        int n = a.length(), m = b.length();

        if (n < m) {
            return "NO";
        }

        // "dp" is the Dynamic Programming based 2-D boolean array
        //     dp[i][j]: boolean indicating whether the first 'i 'characters of 'a' 
        //               can be transformed into the first 'j' characters of 'b'.
        boolean[][] dp = new boolean[n + 1][m + 1];

        // Trivial Base Case: First '0' chars of 'a' already same as first '0' chars of 'b'
        dp[0][0] = true;

        // Initialize dp[i][0]: for 1 <= i <= n, as:
        // First 'i' characters of 'a' can be transformed into first '0' characters of 'b'
        // purely via the deletion operation, which is permitted only on Lowercase Chars.
        for (int i = 1; i <= n; i++) {
            dp[i][0] = dp[i-1][0] && Character.isLowerCase(a.charAt(i-1));
        }

        // Fill the rest of dp[i][j]: for 1 <= i < = n, and for: 1 <= j <= m, as:
        //     (1) IF a[i-1] is Lowercase:
        //           dp[i][j] == (a[i-1] == b[j-1] AND dp[i-1][j-1])
        //     (2) ELSE:
        //           dp[i][j] = (UpperCase(a[i-1]) == b[j-1] AND dp[i-1][j-1]) OR dp[i-1][j]

        for (int i = 1; i <= n; i++) {

            char aCh = a.charAt(i - 1);

            for (int j = 1; j <= m; j++) {

                char bCh = b.charAt(j - 1);

                if (Character.isUpperCase(aCh)) {

                    dp[i][j] = ((aCh == bCh) && dp[i-1][j-1]);

                } else {

                    boolean canCapitalize = 
                        ((Character.toUpperCase(aCh) == bCh) && dp[i-1][j-1]);
                    boolean canDelete = dp[i-1][j];
                    dp[i][j] = canCapitalize || canDelete;

                }

            }

        }

        return (dp[n][m] ? "YES" : "NO");
    }