import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException {
       	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int count = 0;
      	String s = br.readLine();
     	String t = br.readLine();
      	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