import java.util.*;
 
 public class Main {
   	public static void main (String arg[]){
      	Scanner in = new Scanner (System.in);
       	String s = in.nextLine();
      	String t = in.nextLine();
      	
       int count =0;
      for(int i =0; i<3; i++)
      	if (s.charAt(i)==t.charAt(i)){
          count++;
        }
      
      System.out.println(count);
      
      
    }
   
 }
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz