import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner (System.in);
		String s=scan.nextLine();
		String t=scan.nextLine();
		int c=0;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		}
		if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No");

	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner (System.in);
		String s=scan.nextLine();
		String t=scan.nextLine();
		int c=0;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		}
		if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No");

	}

} Main public static void main(String[] args) {
		Scanner scan = new Scanner (System.in);
		String s=scan.nextLine();
		String t=scan.nextLine();
		int c=0;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		}
		if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No");

	} main {
		Scanner scan = new Scanner (System.in);
		String s=scan.nextLine();
		String t=scan.nextLine();
		int c=0;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		}
		if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No");

	} Scanner scan = new Scanner (System.in); scan new Scanner (System.in) String s=scan.nextLine(); s scan.nextLine() scan.nextLine scan String t=scan.nextLine(); t scan.nextLine() scan.nextLine scan int c=0; c 0 for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		} int i=0; int i=0; i 0 i<s.length() i s.length() s.length s i++ i++ i {
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		} {
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		} if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			} s.charAt(i)==t.charAt(i) s.charAt(i) s.charAt s i t.charAt(i) t.charAt t i {
				c+=1;
			} c+=1 c 1 if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No"); t.length()==c+1 t.length() t.length t c+1 c 1 System.out.println("Yes") System.out.println System.out System System.out "Yes" System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner (System.in);
		String s=scan.nextLine();
		String t=scan.nextLine();
		int c=0;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		}
		if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No");

	}

} public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner (System.in);
		String s=scan.nextLine();
		String t=scan.nextLine();
		int c=0;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		}
		if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No");

	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner (System.in);
		String s=scan.nextLine();
		String t=scan.nextLine();
		int c=0;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)==t.charAt(i))
			{
				c+=1;
			}
		}
		if(t.length()==c+1) System.out.println("Yes");
		else System.out.println("No");

	}

}
