import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String s=sc.next();
    String t=sc.next();
    sc.close();
    String predict[]=new String[3];
    String real[]=new String[3];
    int cnt=0;
    for(int i=0;i<3;i++){
      predict[i]=s.substring(i,i+1);
      real[i]=t.substring(i,i+1);
      if(predict[i].equals(real[i])){
        cnt++;
      }
    }
    System.out.println(cnt);
  }
}
/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