import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String args[]){
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String s="", t="";
        try {
            s = br.readLine();
            t = br.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }

        int count = 0;
        for (int i=0; i<3; i++){
            if (s.charAt(i) == t.charAt(i)){
               count++;
            }
        }

        System.out.println(count);
    }
}

/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