import java.util.ArrayList;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
	Scanner sc = new Scanner (System.in);
	int count = 0;
	int whilecount = 0;
	String inputS = sc.next();
	String inputT = sc.next();
	sc.close();

	ArrayList<String> S = new ArrayList<String>();
	ArrayList<String> T = new ArrayList<String>();

	for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	}

	for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	}

	for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	}
	System.out.println(count);
}
} import java.util.ArrayList; ArrayList java.util import java.util.Scanner; Scanner java.util public class Main {
public static void main(String[] args) {
	Scanner sc = new Scanner (System.in);
	int count = 0;
	int whilecount = 0;
	String inputS = sc.next();
	String inputT = sc.next();
	sc.close();

	ArrayList<String> S = new ArrayList<String>();
	ArrayList<String> T = new ArrayList<String>();

	for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	}

	for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	}

	for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	}
	System.out.println(count);
}
} Main public static void main(String[] args) {
	Scanner sc = new Scanner (System.in);
	int count = 0;
	int whilecount = 0;
	String inputS = sc.next();
	String inputT = sc.next();
	sc.close();

	ArrayList<String> S = new ArrayList<String>();
	ArrayList<String> T = new ArrayList<String>();

	for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	}

	for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	}

	for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	}
	System.out.println(count);
} main {
	Scanner sc = new Scanner (System.in);
	int count = 0;
	int whilecount = 0;
	String inputS = sc.next();
	String inputT = sc.next();
	sc.close();

	ArrayList<String> S = new ArrayList<String>();
	ArrayList<String> T = new ArrayList<String>();

	for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	}

	for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	}

	for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	}
	System.out.println(count);
} Scanner sc = new Scanner (System.in); sc new Scanner (System.in) int count = 0; count 0 int whilecount = 0; whilecount 0 String inputS = sc.next(); inputS sc.next() sc.next sc String inputT = sc.next(); inputT sc.next() sc.next sc sc.close() sc.close sc ArrayList<String> S = new ArrayList<String>(); S new ArrayList<String>() ArrayList<String> T = new ArrayList<String>(); T new ArrayList<String>() for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	} int i = 0; int i = 0; i 0 i < inputS.length() i inputS.length() inputS.length inputS i++ i++ i {
		S.add(inputS.substring(i, i+1));
	} {
		S.add(inputS.substring(i, i+1));
	} S.add(inputS.substring(i, i+1)) S.add S inputS.substring(i, i+1) inputS.substring inputS i i+1 i 1 for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	} int i = 0; int i = 0; i 0 i < inputT.length() i inputT.length() inputT.length inputT i++ i++ i {
		T.add(inputT.substring(i, i+1));
	} {
		T.add(inputT.substring(i, i+1));
	} T.add(inputT.substring(i, i+1)) T.add T inputT.substring(i, i+1) inputT.substring inputT i i+1 i 1 for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	} int i = 0; int i = 0; i 0 i < inputS.length() i inputS.length() inputS.length inputS i++ i++ i {
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	} {
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	} if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		} S.get(whilecount).equals(T.get(whilecount)) S.get(whilecount).equals S.get(whilecount) S.get S whilecount T.get(whilecount) T.get T whilecount {

		} {
			count += 1;
		} count += 1 count 1 whilecount += 1 whilecount 1 System.out.println(count) System.out.println System.out System System.out count String[] args args public class Main {
public static void main(String[] args) {
	Scanner sc = new Scanner (System.in);
	int count = 0;
	int whilecount = 0;
	String inputS = sc.next();
	String inputT = sc.next();
	sc.close();

	ArrayList<String> S = new ArrayList<String>();
	ArrayList<String> T = new ArrayList<String>();

	for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	}

	for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	}

	for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	}
	System.out.println(count);
}
} public class Main {
public static void main(String[] args) {
	Scanner sc = new Scanner (System.in);
	int count = 0;
	int whilecount = 0;
	String inputS = sc.next();
	String inputT = sc.next();
	sc.close();

	ArrayList<String> S = new ArrayList<String>();
	ArrayList<String> T = new ArrayList<String>();

	for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	}

	for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	}

	for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	}
	System.out.println(count);
}
} Main
import java.util.ArrayList;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
	Scanner sc = new Scanner (System.in);
	int count = 0;
	int whilecount = 0;
	String inputS = sc.next();
	String inputT = sc.next();
	sc.close();

	ArrayList<String> S = new ArrayList<String>();
	ArrayList<String> T = new ArrayList<String>();

	for(int i = 0; i < inputS.length(); i++) {
		S.add(inputS.substring(i, i+1));
	}

	for(int i = 0; i < inputT.length(); i++) {
		T.add(inputT.substring(i, i+1));
	}

	for(int i = 0; i < inputS.length(); i++){
		if(S.get(whilecount).equals(T.get(whilecount))) {

		}else {
			count += 1;
		}
		whilecount += 1;
	}
	System.out.println(count);
}
}