import java.util.Scanner;

public class Main{

    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);

        // input
        char[] before = scan.next().toCharArray();
        char[] after = scan.next().toCharArray();

        // search
        int answer = 0;
        for(int i = 0; i < 3; i++){
            if(before[i] == after[i]){
                answer++;
            }
        }

        // answer
        System.out.println(answer);

    }
}
/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