import java.util.Scanner;
class Main{
  public static void main(String[] args){
    Scanner scan=new Scanner(System.in);
    String in1=scan.next();
    String in2=scan.next();
    String[] sp1=in1.split("");
    String[] sp2=in2.split("");
    int Ans=0;
    for(int x=0; x<3; x++){
      if(sp1[x].equals(sp2[x])){
        Ans++;
      }
    }
    System.out.println(Ans);
  }
}
/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