#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
  string S,T;
  cin>>S>>T;
  int a = (S[0]-'0')*100+(S[2]-'0')*10+(S[4]-'0');
  int b = (T[0]-'0')*100+(T[2]-'0')*10+(T[4]-'0');
  if(b <= a) cout<<"YES"<<endl;
  else cout<<"NO"<<endl;
}