import java.util.Scanner;
public class Main{
    public static void main(String[]args){
        Scanner scan = new Scanner(System.in);
        String s,t;
        int con;
        s=scan.next();
        t=scan.next();
        con=0;
        for(int i=0;i<3;i++){
            if(s.charAt(i)==t.charAt(i)) con+=1;
        }
        System.out.println(con);
    }
}
/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