#include <iostream>
using namespace std;
int main()
{
int old=0;
for(int i = 0; i < 5; i++){
char c;
cin >> c;
if(i == 0){
old += (c-'0')*100;
} else if(i == 2){
old += (c-'0')*10;
} else if(i == 4){
old += (c-'0');
}
}
int now=0;
for(int i = 0; i < 5; i++){
char c;
cin >> c;
if(i == 0){
now += (c-'0')*100;
} else if(i == 2){
now += (c-'0')*10;
} else if(i == 4){
now += (c-'0');
}
}
if(now <= old){
cout << "YES" << endl;
}else{
cout << "NO" << endl;
}
return 0;
}