import java.util.*;
import java.io.*;
import java.lang.*;

class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    int n =0;
    char a,b;
    String S = scan.nextLine();
    String T = scan.nextLine();
    for(int i = 0; i<3;i++){
        a = S.charAt(i);
        b = T.charAt(i);
      if(a==b){
        n++;}
    }
    System.out.println(n);
  }
}
/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