import java.util.*;
class Main{
    public static void main(String[] Args){
        Scanner scan = new Scanner(System.in);
        String S = scan.next();
        String T = scan.next();
        int hit = 0;
        for(int i = 0;i < 3;i++){
            if(S.charAt(i) == T.charAt(i)){
                hit++;
            }
        }
        System.out.println(hit);
        scan.close();
    }
}
/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