#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ string s; cin>>s; int n=s.length(),y=n; for(int i=0;i<=n/2;i++){ cout<<y<<n<<' '<<s[i]<<endl; if(s[i]!=s[y]){ cout<<"No"; return 0; } y--; } cout<<"Yes"; return 0; }