source_code: import java.util.Scanner;
  
  public class GenerateLogin {
  
  	public static void main(String[] args) {
  		Scanner scan = new Scanner(System.in);
  		String a = scan.next();
  		String b = scan.next();
  		char last = b.charAt(0);
  		String ans = ""+a.charAt(0);
  		for(int i = 1;i<a.length();i++){
  			if(a.charAt(i)>=last)break;
  			ans+=a.charAt(i);
  		}
  		ans+=last;
  		System.out.println(ans);
  	}
  
  }
  