#include<iostream> #include<cstring> using namespace std; int main() { char a[1000]; scanf("%s",a); int n=strlen(a),m=0,k=n-1; while(n%2==1) { if(a[m]==a[k]) { m++; k--; if(m==k) { cout<<"Yes"; break; } } else { cout<<"No"; break; } } while(n%2==0) { if(a[m]==a[k]) { m++; k--; if(a[m+1]==a[k]) { cout<<"yes"; break; } }else{ cout<<"No"; break; } } return 0; }