#include<bits/stdc++.h> using namespace std; int main(){ int n,a,g,s,b,q; cin>>a; g=a%10; s=a/10%10; b=a/100%10; q=a/1000; n=g*1000+s*100+b*10+q; if(a==n+1000<n<9999){ cout<<"yes"; }else{ cout<<"no"; } } /************************************************************** Problem: 1647 User: yangjunwen Language: C++ Result: Wrong Answer ****************************************************************/