#include "bits/stdc++.h"
using namespace std;
#define L long long;
#ifdef LOCAL
#define dbg(x) cerr << "[" << (#x) << " = " << (x) << "]\n";
#else
#define dbg(x)
#endif
// g++ -std=c++17 -O2 -DLOCAL -o a a.cpp

int main() {
  cin.tie(0)->sync_with_stdio(0);
  string s, t; cin >> s >> t;
  int n = s.size(), m = t.size();
  vector<vector<int>> nxt(n, vector<int>(26));
  vector<int> last(26, n);
  for (int i = n - 1; i >= 0; i--) {
    nxt[i] = last;
    last[s[i] - 'a'] = i;
  }
  int64_t ans = 0;
  for (int i = 0; i < n; i++) {
    int cur = i;
    int start = 0;
    if (s[i] == t[0]) start = 1;
    for (int j = start; j < m; j++) {
      if (cur == n) break;
      cur = nxt[cur][t[j] - 'a'];
    }
    ans += n - cur;
  }
  cout << ans << '\n';
}