#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
char s[N], t[N];
int ne[N][26];
int n, m;
int main() {
    scanf("%s%s", s + 1, t + 1);
    n = strlen(s + 1); 
    m = strlen(t + 1);
    for (int d = 0; d < 26; ++d) ne[n + 1][d] = n + 1;
    for (int i = n; i; --i) {
        memcpy(ne[i], ne[i + 1], sizeof ne[i]);
        ne[i][s[i] - 'a'] = i;
    }
    long long ans = 0;
    for (int i = n; i; --i) {
        int cur = i - 1;
        for (int j = 1; j <= m && cur != n + 1; ++j) cur = ne[cur + 1][t[j] - 'a'];
        // printf("%d %d\n", i, cur);
        ans += n + 1 - cur;
    }
    printf("%lld\n", ans);
    return 0;
}