#include<bits/stdc++.h> using namespace std; int main(){ char s[10000]; int i,n,f=1; cin>>s>>n; for(i=0;i<=n/2;i++){ if(s[i]!=s[n-1-i]){ f=0; break; } } if(f){ cout<<"yes"<<endl; }else{ cout<<"no"<<endl; } return 0; }