import collections

def _check(a, b):
    if len(a)==1:
        if len(b)==0:
            return a[0].islower()
        else:    
            return a[0].upper()==b[0]
    if a[-1]==b[-1]:
        return _check(a[:-1], b[:-1])
    elif a[-1].upper()==b[-1]:
        return _check(a[:-1], b) or _check(a[:-1], b[:-1]) 
    else:
        return a[-1].islower() and _check(a[:-1], b)
   
def _upper(s, i):
    return s[0:i]+s[i].upper()+s[i+1]


def _remove_unused(a, b):
    _set_b=set(b)
    return "".join(list([x for x in a if x.isupper() or x.upper() in _set_b]))
    

def _build_dp(a):
    _dp = collections.defaultdict(int)
    for _, x in enumerate(a):
       _dp[x.upper()]+=1
    return _dp

def _precheck_check_dp(dp_a, dp_b):
    for x in dp_b:
        if dp_a[x] < dp_b[x]:
            return False
    return True


def abbreviation(a, b):
    a=_remove_unused(a, b)
    if len(a)<len(b):
        return "NO"        
    if not _precheck_check_dp(_build_dp(a),_build_dp(b)):
        return "NO"
    if _check(a, b):
        return "YES"
    else:
        return "NO"

string abbreviation(string a, string b) {
    int j = 0;
    map<char, int> dp1, dp2;
    for(int i = 0;i<a.size();i++)
    {
        dp1[a[i]]++;
    }
    
    for(int i = 0;i<b.size();i++)
    {
        dp2[b[i]]++;
    }
    
    for(int i = 0;i<b.size();i++)
    {
        dp1[b[i]]--;
        if(dp1[b[i]] < 0)
        {
            dp1[char(b[i]+32)]--;
            if(dp1[char(b[i]+32)] < 0)
                return "NO";
        }
    }
    
    for(int i = 0;i<b.size();i++)
    {
        if(dp1[b[i]]>0)
            return "NO";
    }
    
    for(int i = 0;i<a.size();i++)
    {
        if(dp1[a[i]]>0 && a[i]<='Z')
            return "NO";
    }
    
    for(int i = 0;i<a.size();i++)
    {
        if(a[i] <= 'Z' && dp2.find(a[i]) == dp2.end())
            return "NO";
    }
    
    for(int i = 0;i<a.size();i++)
    {
        if(j < b.size())
        {
            if(a[i] == b[j] || char(a[i]-32) == b[j])
            {
                j++;
            }
        }
    }
    
    if(j == b.size())
    {
        return "YES";
    }
    return "NO";
}