#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
typedef long long int lld;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define trav(a,v) for(auto a:v)
int nxt[1000000][26];
void solve(){
	string s,t;
	cin>>s>>t;
	int n=s.size();
	rep(i,0,26)nxt[n+1][i]=n+1;
	rep(i,0,26)nxt[n][i]=n+1;
	for(int i=n-1;i>=0;i--){
		rep(j,0,26)nxt[i][j]=nxt[i+1][j];
		nxt[i][s[i]-'a']=i+1;
	}
	lld ans=0;
	rep(i,0,n){
		int place=i;
		rep(j,0,(int)t.size()){
			place=nxt[place][t[j]-'a'];
		}
		ans+=n-place+1;
	}
	cout<<ans<<"\n";
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt=1;
	//cin>>tt;
	while(tt--){
		solve();
	}
}