import java.util.*;

class Main{
  
  public static void main(String [] args)
  {
 		Scanner sc  = new Scanner(System.in);
    	String F =sc.nextLine();
    	String C =sc.nextLine();
    	int count=0;
    	for(int i=0;i<F.length();i++)
        {
          Character c1 = F.charAt(i);
          Character c2 = C.charAt(i);
          
          if(c1==c2) 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