import java.util.*;
public class Main{
        public static void main(String[] args){
                Scanner コロナ = new Scanner(System.in);
                String わたし = コロナ.next();
                String あなた = コロナ.next();
                コロナ.close();
                int yoﾉ = 0;
                for(int i = 0 ; i < 3 ; i++){
                        if(わたし.charAt(i) == あなた.charAt(i)) yoﾉ++;
                }
                System.out.println(yoﾉ);
        }
}
/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