#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() using namespace std; int main(){ char s[101]; int n,i,flag=1; cin>>s; cin>>n; for(i=0;i<=n/2;i++){ if(s[i]!=s[n-1-i]){ flag=0; } } if(flag){ cout<<"YES"<<endl;} else{ cout<<"NO"<<endl; } return 0; }