import java.util.Scanner;

public class Main {

	/*
	 * 文字列を分割して回数を数える
	 */
	public static void main(String[] args) {

		Scanner s = new Scanner(System.in);

		String yosou = s.next();
		String kekka = s.next();

		s.close();

		String[] yosou1 = yosou.split("");
		String[] kekka1 = kekka.split("");
		int count = 0;
		for (int i = 0; i < 3; i++) {
			if (yosou1[i].equals(kekka1[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