import java.util.*;
 
class Main{
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
  String s1=sc.nextLine();
  String s2=sc.nextLine();
  int count=0,i;
  for(i=0;i<s1.length();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