#include <bits/stdc++.h>

using namespace std;

int main() {
string j, s;
cin » j » s;
vector <int> J(27,0), S(27, 0);
for (size_t i = 0; i < j.size(); ++i) {
J[j[i] - 'a']++;
}
for (size_t i = 0; i < s.size(); ++i) {
S[s[i] - 'a']++;
}
int res = 0;
for (size_t i = 0; i < 27; ++i) {
if (J[i])
res += S[i];
}
cout « res;
return 0;
}