import java.util.Scanner;

public class Main{
  public static void main(String[] args){

    Scanner sc = new Scanner(System.in);

    String S = sc.next();
    String T = sc.next();

    int count = 0;

    for(int i = 0; i < 3; i++){
      if(S.substring(i,i + 1).contains(T.substring(i,i + 1))){
       count = count + 1;
      }
    }
    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