#include <iostream>
#include <string>
#include <vector>
#include <cmath>
using namespace std;
int main()
{
	string s1,s2;
	cin>>s1>>s2;
	vector<int> a(27,0),b(27,0);
	for(int i=0;i<s1.size();++i)
		++a[s1[i]-'a'];
	for(int j=0;j<s2.size();++j)
		++b[s2[j]-'a'];
	int ans=0;
	for(int i=0;i<a.size();++i)
		ans+=abs(a[i]-b[i]);
	cout<<ans;
}