import  java.util.Scanner;
//import jaava.util.InputMismatchException;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s1 = sc.next();
    String s2 = sc.next();
    int count=0,i;
    for(i=0;i<3;i++){
      if(s1.charAt(i)==s2.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