bool is_upper(char a)
{
    if (a >= 'A' && a <= 'Z') return true;
    return false;
}

char to_upper(char a)
{
    return (char)(a - 32);
}

// Complete the abbreviation function below.
string abbreviation(string a, string b) {
    bool success = false;
    char pre_check = '0';

    int checka = 0, checkb = 0;

    while (checka < a.length())
    {
        if (is_upper(a[checka]))
        {
            if (a[checka] != b[checkb])
            {
                if (a[checka] != pre_check)
                {
                    success = false;
                    break;
                }
            }
        }
        if (a[checka] == b[checkb] || to_upper(a[checka]) == b[checkb])
        {
            if (is_upper(a[checka])) pre_check = a[checka];
            else pre_check = to_upper(a[checka]);
            checkb++;
            if (checkb == b.length())
            {
                success = true;
                for (int i = checka + 1; i < a.length(); i++)
                {
                    if (is_upper(a[i]))
                    {
                        success = false;
                        break;
                    }
                }
                break;
            }
        }
        checka++;
    }

    if (success) return "YES";
    else return "NO";

}