#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(){ char c[1001]; cin>>c; int n; for(int i=0;c[i]!='\0';i++) n++; bool f=true; for(int i=0;i<=n/2;i++){ if(s[i]!=s[n-1-i]) {f=false;break;} } if(f==false) cout<<"no"<<endl; else cout<<"yes"<<endl; return 0; }