import java.util.*;
import java.math.*;
import java.lang.*;
import java.io.*;
 
public class Main{
  public static void main(String args[]) throws IOException{
    Scanner s=new Scanner(System.in);
   
    String ss=s.nextLine();
    String tt=s.nextLine();
    
    int c=0;
    for(int i=0;i<3;i++){
      if(ss.charAt(i)==tt.charAt(i))
        c++;
    }
    System.out.println(c);
  }
}
    
    
  
/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