import java.util.*;
public class Main {
	Scanner sc;
	String S,T;

	public Main() {
		sc = new Scanner(System.in);
	}
	
	private void calc() {
		S = sc.next();
		T = sc.next();
		int c = 0;
		for (int i = 0; i < 3; i++) {
			if (S.charAt(i) == T.charAt(i)) c++;
		}
		System.out.println(c);
		System.out.flush();
	}

	public static void main(String[] args) {
		new Main().calc();
	}

}
/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