#include<bits/stdc++.h>
using namespace std;
int main(){
	char a[1001],b[1001];//我
	cin>>a>>b;
	int lena=strlen(a),lenb=strlen(b);//是
	if(lena<lenb||lena==lenb&&strcmp(a,b)<0){
		cout<<"YES";//水
	}else{
		cout<<"NO";//印
	}
	return 0;
}