cin>>ch;
    for(i,0,26)t[i]=0;
    n=ch.size();
    if(n==1){cout<<"No";return 0;}
    for(i,0,n)t[ch[i]-'a']++;
    for(i,0,26)if(t[i]>n/2+n%2){cout<<"No";return 0;}
    cout<<"Yes";