#include<bits/stdc++.h>
using namespace std;
#define sz(s) int((s).size())
const int AL = 26;
const int N = 2e5 + 10;
 
string s, t;
int pre[N], suff[N], pos[AL], ind;
 
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
 
	cin >> s >> t;
	for(int i = 0; i < sz(s); ++ i){
		if(ind < sz(t) && s[i] == t[ind])
			pos[s[i] - 'a'] = ind ++;
		pre[i] = pos[s[i] - 'a'];
	}
	ind = sz(t) - 1; memset(pos, 0, sizeof(pos));
	for(int i = sz(s) - 1; i >= 0; -- i){
		if(ind >= 0 && s[i] == t[ind])
			pos[s[i] - 'a'] = sz(t) - (ind --);
		suff[i] = pos[s[i] - 'a'];
	}	
	
	for(int i = 0; i < sz(s); ++ i)
		if(pre[i] + suff[i] < sz(t)) return cout << "No\n", 0;
	cout << "Yes\n";
	
	return 0;
}