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