import java.io.*;

import java.util.*;

public class TestClass {

public static void main(String[] args) throws IOException {

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

PrintWriter wr = new PrintWriter(System.out);

String A = br.readLine();

String P = br.readLine();

int out_ = count_like_dislike(A, P);

System.out.println(out_);

wr.close();

br.close();

}

static int count_like_dislike(String A, String P){

int count=0;

for(int i=0;i<A.length();i++)

{

char val1 = A.charAt(i);

char val2 = P.charAt(i);

if(val1 == val2)

{

count++;

}

}

return count;

}

}