#include<bits/stdc++.h>

 #define LL long long

 #define  N 100005

 using namespace std;

 inline int ra()

 {

     int x=,f=; char ch=getchar();

     while (ch<'' || ch>'') {if (ch=='-') f=-; ch=getchar();}

     while (ch>='' && ch<='') {x=x*+ch-''; ch=getchar();}

     return x*f;

 }

 char s[N<<],t[N<<];

 int L[N<<],R[N<<],last[N<<];

 int main()

 {

     scanf("%s%s",s,t);

     memset(last,-,sizeof(last));

     int j=,slen=strlen(s),tlen=strlen(t);

     for (int i=; i<slen; i++)

     {

         L[i]=last[s[i]-'a'];

         if (j<tlen && s[i]==t[j])

         {

             L[i]=j;

             j++;

         }

         last[s[i]-'a']=L[i];

     }

     memset(last,-,sizeof(last));

     j=tlen-;

     for (int i=slen-; i>=; i--)

     {

         R[i]=last[s[i]-'a'];

         if (j>= && s[i]==t[j])

         {

             R[i]=j;

             j--;

         }

         last[s[i]-'a']=R[i];

     }

     bool ok=;

     for (int i=; i<slen; i++)

         if (L[i]==- || R[i]==- || L[i]<R[i])

         {

             ok=;

             break;

         }

     ok?puts("Yes"):puts("No");

     return ;

 }