import java.util.*;
public class Main{
	public static void main(String args []){
    	Scanner sc=new Scanner(System.in);
      	char a[]=sc.next().toCharArray();
      	char b[]=sc.next().toCharArray();
      	int count=0;
      	for(int i=0;i<a.length;i++){
        	if(a[i]==b[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