import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String S = br.readLine();
        String T = br.readLine();
        
        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