// MEMOIZED IMPLEMENTATION

#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define ld long double
#define ull unsigned long long
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define F first
#define S second
#define PI 3.1415926535897932384626
#define sz(x) ((int)(x).size())

typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ull> vull;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<vull> vvull;
typedef vector<vb> vvb;
typedef vector<vc> vvc;

/************************************************** DEBUGGER *******************************************************************************************************/

#ifndef ONLINE_JUDGE
#define debug(x) cerr << #x <<" "; _print(x); cerr << endl;
#else
#define debug(x)
#endif

void _print(ll t) { cerr << t; }
void _print(int t) { cerr << t; }
void _print(string t) { cerr << t; }
void _print(char t) { cerr << t; }
void _print(ld t) { cerr << t; }
void _print(double t) { cerr << t; }
void _print(ull t) { cerr << t; }

template <class T, class V> void _print(pair <T, V> p);
template <class T> void _print(vector <T> v);
template <class T> void _print(vector <vector<T>> v);
template <class T> void _print(set <T> v);
template <class T, class V> void _print(map <T, V> v);
template <class T> void _print(multiset <T> v);
template <class T, class V> void _print(pair <T, V> p) { cerr << "{"; _print(p.F); cerr << ","; _print(p.S); cerr << "}"; }
template <class T> void _print(vector <T> v) { cerr << "[ "; for (T i : v) {_print(i); cerr << " "; } cerr << "]"; }
template <class T> void _print(vector <vector<T>> v) { cerr << "==>" << endl; for (vector<T> vec : v) { for(T i : vec) {_print(i); cerr << " "; } cerr << endl; } }
template <class T> void _print(set <T> v) { cerr << "[ "; for (T i : v) {_print(i); cerr << " "; } cerr << "]"; }
template <class T> void _print(multiset <T> v) { cerr << "[ "; for (T i : v) {_print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void _print(map <T, V> v) { cerr << "[ "; for (auto i : v) {_print(i); cerr << " "; } cerr << "]"; }

/*******************************************************************************************************************************************************************/

mt19937_64 rang(chrono::high_resolution_clock::now().time_since_epoch().count());
int rng(int lim) {
    uniform_int_distribution<int> uid(0,lim-1);
    return uid(rang);
}

const int INF = 0x3f3f3f3f;
const int mod = 1e9+7;

ll mod_exp(ll a, ll b) { a %= mod; if(a == 0) return 0LL; ll res = 1LL;
                         while(b > 0) { if(b & 1) res = (res * a) % mod; a = (a * a) % mod; b >>= 1; } return res; }

ll mod_inv(ll a) { return mod_exp(a, mod - 2); } // works only for prime value of "mod"
ll GCD(ll a, ll b) { return (b == 0) ? a : GCD(b, a % b); }

/******************************************************************************************************************************/

vvi dp;

int cnt_ways(string &s1, string &s2, int n, int m) {
    // base case(s)
    if(n == 0 and m != 0) return 0;
    if(n < m) return 0;
    if(n == 0 or m == 0) return 1;

    // check if already calculated or not
    if(dp[n][m] != -1) return dp[n][m];

    if(s1[n-1] == s2[m-1]) {
        return dp[n][m] = cnt_ways(s1, s2, n - 1, m) + cnt_ways(s1, s2, n - 1, m - 1);
    }

    else return dp[n][m] = cnt_ways(s1, s2, n - 1, m);
}

void solve()
{
    string s1, s2; cin >> s1 >> s2;

    int n = sz(s1);
    int m = sz(s2);

    dp.clear();
    dp.resize(n + 1, vi(m + 1, -1));

    cout << cnt_ways(s1, s2, n, m) << "\n";
}

int main()
{
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    srand(chrono::high_resolution_clock::now().time_since_epoch().count());

    // #ifndef ONLINE_JUDGE
    //     freopen("input.txt", "r", stdin);
    //     freopen("output.txt", "w", stdout);
    // #endif

    // #ifndef ONLINE_JUDGE
    //      freopen("error.txt", "w", stderr);
    // #endif

    int t = 1;
    // int test = 1;
    // cin >> t;
    while(t--) {
        // cout << "Case #" << test++ << ": ";
        solve();
    }

    return 0;
}