import java.util.*;
public class Main {
public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
  	int cnt = 0;
 	String S = sc.next();
  	String T = sc.next();
  	char[] s_arr = S.toCharArray();
	char[] t_arr = T.toCharArray();
  
  	for (int i=0;i<3;i++){
      	if (s_arr[i] == t_arr[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